EPA-AA-IMS/80-10
Evaluation of the Applicability
of Inspection/Maintenance Tests
On A Chevrolet Camero Z-28
December 1980
Bill Smuda
NOTICE
Technical Reports do not necessarily represent final EPA decisions or posi-
tions. They are intended to present technical analysis of issues using data
which are currently available. The purpose in the release of such reports is
to facilitate the exchange of technical information and to inform the public
of technical developments which may form the basis for a final EPA decision,
position or regulatory action.
Inspection/Maintenance Staff
Emission Control Technology Division
Office of Mobile Source Air Pollution Control
U.S. Environmental Protection Agency
Ann Arbor, Michigan 48105
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ABSTRACT
This report presents test results which were gathered to determine the suit-
ability of existing I/M short tests on a Chevrolet car with a computer based
emission control system. This car had a microprocessor based engine control
system with a dual bed catalyst . After suitable baslines were established,
various components were made inoperative in the emission control system.
Complete FTP, HFET and I/M tests were run for each vehicle condition. Also an
on-board system diagnostic check was performed for each configuration after
the initial baselines.
This report presents the measured data taken during the tests.
BACKGROUND
Beginning with the 1981 model year, electronics and computers will control
many of the vital functions of automotive operation now regulated by mech-
anical means. As the Inspection/Maintenance effort is expanded it is a
prerequisite that the test procedure used by Inspection/Maintenance programs
be capable of identifying 1981 and later model year vehicles with equipment
failure and parameter maladjustment. With the advent of the use of advanced
electronics into automobiles, it is necessary to evaluate the suitability of
existing and proposed I/M tests to these future automobiles. To accomplish
this evaluation, several prototype and early production cars containing
representative electronics of the future have been tested according to both
the Federal Test Procedures and I/M test procedures. The data obtained should
indicate which I/M test best suits these automobiles. This report presents
the data collected on the fifth such automobile tested by EPA, a 1981
Chevrolet Camaro Z-28 with a microprocessor controlled emission control system.
HISTORY
The Chevrolet Camaro Z-28 is a 1981 production vehicle purchased by EPA from a
local Chevrolet dealer. This particular vehicle, which has a Federal emission
package, was delivered to EPA on 1 October 1980 with 30 miles on the
odometer. Break-in mileage was accumulated utilizing repeated LA-4 and HFET
cycles in a ratio of about 4 LA-4's per HFET. Since this vehicle was origin-
ally procured for use in a different long term EPA test project which was on a
very tight timetable, the decision was made to accomplish the I/M test project
with relatively few miles on the vehicle. At 233 accumulated miles, I/M
baseline testing started.
After two baseline sequences were run, the vehicle was tested with seven
different component deactivations. Two final confirmatory baseline sequences
were then run. The testing was completed on 5 November 1980.
TESTING PROCEDURE
In order to test the vehicle the following test sequence was used:
a. Federal Test Procedure (FTP) 1979 procedure, non-evaporative, no heat
build.
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b. 50 MPH Cruise. This test consists of a three minute steady state run
at 50 MPH. HC and CO measurements are taken with a garage type analyzer.
This test is performed with the hood open and fan on. The three minute 50
MPH cruise also serves as preconditioning for the highway fuel economy
test.
c. Highway Fuel Economy Test (HFET). Immediately after the 50 MPH cruise.
Each of the following steps required a six minute idle preconditioning, hood
open, fan on.
d. Four Mode Idle Test with raw EC/CO garage type analyzer. Emissions
were tested at Idle (neutral), 2500 rpm, Idle (neutral), and Idle
(drive). The hood was open and the fan was on.
e. Loaded Two Mode. Raw HC and CO measurements were taken with the
dynamometer set at 9.0 A.H.P. at 30 MPH with the I.W. = 1750 pounds.
Immediately afterward, measurements were taken at idle (neutral) using a
garage type analyzer. The hood was open and the fan was on.
f. Propane Injection Procedure for three way catalyst vehicles. A
description of this test and a sample data sheet are given in Attachment 1.
Note: This propane injection procedure is still in the development stage.
Some difficulties were encountered by the technicians in applying this
test to this vehicle. In some tests tachometer fluctuations mask the
theoretically expected results. Bear in mind when reviewing the obtained
data that this is still an experimental procedure.
g. On-Board System Diagnostic Check. This check took advantage of the
on-board self-diagnostic system used on 1981 GM products. See Attachment
3 for a description of the system.
I/M test HC and CO measurements were recorded before and after the dual bed
catalyst. A worksheet recording the I/M test results is shown in Attachment 2.
VEHICLE DESCRIPTION
The Chevrolet Camaero Z-28 used for this testing was a production vehicle with
a Federal Emission Package. The most important components of this auto-
mobile's emission control system were the sensors, actuators, and the micro-
processor unit. A complete description of these components is given in
Attachment 3. Attachment 4 lists specific vehicle parameters.
BASELINE DATA
To accurately determine the effect of the various component deactivations, it
was necessary to have an accurate baseline determined for each pollutant in
each mode of every test type. This baseline data is displayed with the
component deactivation data.
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TEST CONFIGURATIONS
After the baseline testing was completed, various components of the emission
control system were, one by one, deactivated prior to vehicle testing.
Configurations a, b and c were run with power to the air control solenoid
interrupted in addition to the listed system disablements. Computer control
of this solenoid is accomplished by switching the ground side of this
solenoid.!/
This malfunction may be realized in several ways. The malfunction may be
induced by deliberate tampering, by improper maintenance i.e. pulling on wires
to disconnect an electrical connection may result in an open circuit, or by
computer failure. The former cases will not be sensed by the computer. The
latter case may be indicated in the diagnostic check dependent on the computer
failure mode.
a. Mixture control solenoid disconnected - Test numbers 80-6335 and
80-6336 were run with the mixture control solenoid (MCS) disconnected.
When the system is operating properly, this solenoid oscillates at the
duty cycle determined by the microprocessor. The duty cycle determines
the fuel/air ratio. With this device deactivated the system defaults to a
full rich condition.
b. Coolant temperature sensor disconnected - Test numbers 80-6337 and
80-6338 were run with the coolant temperature sensor (CTS) disconnected.
Because the oxygen sensor does not perform properly until it reaches a
specified temperature, the coolant sensor informs the feedback control
system to operate in open-loop mode until temperature is reached. With
the CTS disconnected the system runs in an open-loop, cold mode.
c. Throttle position sensor disconnected - Test numbers 80-6339 and
80-6340 were run with the throttle position sensor (TPS) electrically
disconnected. This sensor provides the microprocessor with information
regarding the throttle blade angle. Disconnecting this device gives a
fixed throttle input to the. microprocessor.
The remaining configurations were run with power to the air control solenoid
enabled. This provides normal microprocessor-controlled air routing which
routes the secondary air to the air cleaner during any perceived system
failure. With the secondary air system functioning normally, the ultimate
destination of secondary air is the same as for other GM systems with a
different air routing configuration given a similar set of computer inputs.
_!/ In most GM air management system applications the air control valve routes
air to the air cleaner when energized and to the air switching valve when
de-energized. The air switching valve routes air to the ports when energized
and to the dual bed catalytic converter when de-energized. In this particular
application air is supplied to the catalytic converter when the control valve
is de-energized and to the air switching valve when energized. The air
switching valve routes air to the ports when de-energized and to the air
cleaner when energized.
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d. Mixture control solenoid disconnected - Test numbers 80-6344 and
80-6625 were run with the MCS disconnected.
e. EGO sensor lead disconnected and short circuited - Test numbers
80-6626 and 80-6627 were run with the exhaust gas oxygen (EGO) sensor
disconnected with the microprocessor input lead shorted. Shorting the EGO
sensor lead guaranteed a zero voltage input to the microprocessor. These
tests were designated EGO shorted.
f. Throttle position sensor disconnected - Test numbers 80-6628 and
80-6629'were run with the TPS disconnected.
g. EGO disconnected lead open circuited - Test numbers 80-6630 and 80-6631
were run with the exhaust gas oxygen sensor disconnected. The EGO sensor
supplies a voltage signal to the microprocessor based on the oxygen
content of the exhaust stream. By disconnecting this sensor and leaving
the lead open circuited the senses a near zero voltage and the closed loop
systems is deactivated. These tests were designated EGO sensor dis-
connected.
TEST RESULTS
The test results are given in several attachments.
a. The FTP and HFET results are given in attachment 5. The HC, CO, C02
and NOx readings are in grams/mile while fuel economy is in miles per
gallon.
b. Attachment 6 presents the standard I/M test data. Values are given for
readings taken before and after the catalyst.
c. Attachment 7 presents the results of the propane injection diagnostic
procedure for three-way catalyst vehicles.
d. Attachment 8 presents the results of the on-board system diagnostic
check.
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ATTACHMENT 1
Propane Injection Diagnostic Procedure for Three-Way Catalyst Vehicles
The purpose of this procedure is to identify a failed feedback control
system. If a running engine with a functioning feedback control system is
suddenly given a volume of propane gas, the engine should give a characteris-
tic response: the CO emission levels, and engine speed, should first increase,
but then return to normal as the carburetor compensates for the richer
mixture. If the feedback system is not functioning, the carburetor will be
unable to compensate (i.e. lean out the mixture) for the presence of the
programs. In this case the CO levels and engine speed will simply rise (or
possibly fall) without returning to normal.
For this experimental procedure, four propane gas flow rates were used for
each vehicle: 1, 2, 3, and 4 cubic feet per hour (cfh). Each rate was pre-set
with a flowmeter, and then suddenly presented to the carburetor through an
inlet to the air cleaner. A large bottle of propane was purchased for this
project, and a system of regulators was attached to easily set the flow rates.
The vehicle was at curb idle in Neutral or Park gear, fully warmed-up, and all
accessories off. Before each measurement the- engine speed was increased to
approximately 2500 rpm in neutral gear for 30 seconds. The propane was
admitted within 30 seconds after the engine was returned to idle. Readings
were taken within 60 seconds after the propane was flowing. The propane flow
was then shut off to the vehicle and further readings were taken and recorded.
One data sheet was filled out for each flow rate. If a flow rate caused the
engine to stall, notation of that was made at step 3 of the data sheet and the
procedure stopped for that vehicle.
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Propane Injection Diagnostic Procedure for Advanced Technology Vehicles
Vehicle #
Make/Model
Date
CID
1. Preset Flow Rate. Record Flow Rate cfh
Operate engine at 2500 RPM for 30 seconds, then return to idle.
2. Record: Idle RPM (Neutral/Park gear, no propane flowing)
ICO
3. Induce propane quickly, observe vehicle behavior over a period not larger
than 60 seconds.
Codes Check one:
1 RPM rises smoothly
2 RPM decreases smoothly
3 RPM rises smoothly to (record RPM), then falls.
4 RPM falls smoothly to • (record RPM), then rises.
5 Engine runs rough, then stabilizes
6 Engine dies (stop procedure here)
7 No Change
4. When engine stabilizes (maximum 60 seconds) record: RPM
ICO
5. Withdraw propane quickly, observe vehicle behavior
Codes Check one:
1 RPM rises smoothly
2 RPM decreases smoothly
3 RPM rises smoothly to (record RPM), then falls.
4 RPM falls smoothly to (record RPM), then rises.
5 Engine runs rough, then stabilizes
6 Engine dies
7 No Change
6. When engine stabilizes record: RPM
ICO
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ATTACHMENT 2
DATE
DISABLEMENT
DISABLEMENT TESTING - SHORT TEST DATA SHEET
TEST NO. VEHICLE
OPERATOR
Before
Catalysts
After
Catalysts
50 MPH Cruise
4 Speed Idle
Idle (N)
2500 RPM
Idle (N)
Idle (M)
2 Mode Loaded
Loaded* (Pendant Mode)
Idle (N)
HC
CO
HC
CO
* The loaded mode is a 30 mph cruise @ 9.0 AHP.
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COMPUTER COMMAND CONiHOL 6E1-.1
ATTACHMENT 3
SECTION 6E1
COMPUTER COMMAND CONTROL SYSTEM
CONTENTS
General Description 6E1—1
System Description .• 6E1—1
Electronic Control Module 6E1—1
Coolant Sensor 6E1—3
Pressure Sensors 6E1—3
Fuel Control System 6E1—3
Mixture Control Solenoid 6E1—3
Oxygen. Sensor , 6E1—3
System Operation 6E1—3
Electronic Spark Timing 6E1—4
Electronic Spark Control and EST 6E1—6
Air Management 6E1—6
Exhaust Gas Recirculation 6E1—6
Evaporative Emission Control System 6EJ—6
Early Fuel Evaporation : 6E1—7
Transmission Converter Clutch 6E1—7
Wiring Harness and Connectors 6E1—7
Diagnosis <>E1—7
General '. ~. 6E1—8
Tool and Equipment 6E1—8
Diagnostic Circuit Check 6E1—9
Clearing Trouble Code Memory 6E1—9
Driver Complaint 6E1—12
System Performance Check '. 6E1—12
Trouble Code Identification : 6E1—12
Other System Diagnosis 6E1—12
On-Car Service 6E1—50
General 6E1—50
Electronic Control Module 6E1—50
PROM Replacement 6E1—50
Coolant Sensor 6E1 50
Pressure Sensor 6E1—54
Oxygen Sensor 6E1—54
Model E2SE Carburetor 6E1 54
Idle Mixture Calibration 6E1—54
TPS Adjustment 6E1—55
M/C Solenoid Replacement 6E1—55
ISC Replacement „ 6E1—55
Model E2ME/E4ME Carburetor .' 6E1—55
Calibration 6E1—55
Checking M/C Solenoid 6E1—56
Mixture Control Adjustment 6E1—56
Checking M/C Solenoid Travel 6E1—56
M/C Solenoid Adjustment 6E1—57
Idle Air Bleed Valve Adjustment 6E1—57
Idle Mixture Adjustment 6E1—59
TPS Adjustment 6EI—59
Model 6510-C Carburetor 6E1—59
M/C Solenoid Check.... '. 6E1—59
M/C Solenoid Replacement ,. 6E1—60
Idle Mixture Adjustment 6E1—60
TPS Replacement 6E1—61
TPS Adjustment 6E1—61
Cold Start Program Modifier 6E1—61
Electronic Spark Timing 6E1—64
Ignition Timing 6E1—64
Transmission Convener Clutch 6E1—64
Wiring Harness Service 6E1—65
Glossary of Terms £E)—76
GENERAL DESCRIPTION
SYSTEM DESCRIPTION
The Computer Command Control system (Fig. 6E1-1)
is an electronically controlled exhaust emission system that
monitors up to fifteen (15) different engine/vehicle
functions and can control as many as nine (9) different
operations including the transmission converter clutch (Fig.
6E1-1A). The system has back-up programs in the event
of a failure to alert or instruct the operator through a
"CHECK ENGINE" lamp on the instrument panel. This
lamp will light indicating a fault in the system and will
remain "on" until problem is corrected. This same lamp
through an integral diagnostic system, will aid the
technician in locating the cause of the problem area.
The system helps to lower exhaust emissions while
maintaining good fuel economy and driveability. The
system controls the following operations:
• Fuel Control System
w Electronic Spark Timing (EST)
• Electronic Spark Control and EST
• Air Management
• Exhaust Gas Recirculation System
• Evaporative Emission Control System
• Early Fuel Evaporation
• Transmission Converter Clutch
Electronic Control Module (ECM)
The electronic control module (ECM) located in the
passenger compartment, * is the control center of the
Computer Command Control system. The ECM controls
the Computer Command Control system by constantly
monitoring engine function. Information regarding cooling
system temperature, crankshaft rpm, throttle blade position,
manifold pressure and the amount of oxygen in exhaust
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6E/I-2 COMPUTER COMMAND CONTROL
10
ELECTROMECHANICAL
CARBURETOR
ELECTRONIC
CONTROL MODULE
(ECM)
THROTTLE POSITION
SENSOR
BAROMETRIC
PRESSURE
SENSOR
IDLE SPEED
ACTUATOR
EST
DISTRIBUTOR
DIAGNOSTIC LIGHT
MANIFOLD PRESSURE
SENSOR
CHARCOAL
CANISTER
PURGE
OXYGEN
SENSOR
j DUAL BED
HI j CATALYTIC
i / | CONVERTER
COOLANT
SENSOR
AIR PUMP &
MANAGEMENT VALVE
CONVERTER
CLUTCH
Fig. 6E1-1—Computer Command Control System-Typical
MONITORED PARAMETERS
• Exhaust Oxygen Concentration
• Engine Coolant Temperature
• Throttle Position
• Barometric Pressure
• Manifold Pressure (Absolute or Differential)
• Engine Crankshaft Position
• Battery Voltage
• Vehicle Speed
• Transmission Gear Indication and/or
Carburetor Air Inlet Temperature
• Park/Neutral Mode
• Brake Pedal Engagement
• A/C Clutch Engagement
• Throttle Actuator Contact Switch Engagement
• Time (Internally Generated within ECM)
• Cold Start Program Modifier Condition
ELECTRONIC
CONTROL
MODULE
(ECM)
CONTROLLED PARAMETERS
Carburetor M/C Solenoid Signal
• AIR Control Valve Signal
AIR Switching Valve Signal
Electronic Spark Timing Signal
• Canister Purge Valve Signal
• Torque Converter Clutch Signal
• EGR Control Valve Signal
• EFE Control Valve Signal
• Idle Speed Control Signal
Not all features are used on all engines'.
208851
Fig. 6E1-1A—System Parameters
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JJL
ECU
REFERENCE
EXO ICU
KAif *00*D MHftENCE
•OUXD KntEUMM t»D
DUUIKXMD
Fig. 6E1-2—ECM-PROM Identification
gases is .continuously fed into the ECM while the engine is
running. The ECM is designed to process this information
and programmed to send the necessary electrical responses
to control the Computer Command Control system. The
ECM contains a engine calibration unit called a PROM
(Fig. 6E1-2) which is located under an access cover. The
PROM contains specific instructions to tailor each ECM to
each car design such as:
• Car size and weight
• Engine
• Transmission
• Final Drive Ratio
When a PROM has been programmed for a particular
car, it cannot be used on another car that does not have the
same standards.
The ECM also monitors the engine crankshaft posiiion
signal in order to determine engine RPM.
Coolant Sensor (Fig. 6E1-3)
The coolant sensor is mounted in the engine coolant
stream. It has a high resistance (around 100,000 ohms)
when the coolant is cold and a low resistance (under 1,000
ohms) when the coolant is warm. The sensor sends
information on engine temperature to the ECM which is
used for the following:
• To vary the air-fuel ratio as the engine coolant
temperature varies with time during a cold start.
Fig. 6E1-3—Coolant Temperature Sensor
• To accomplish various switching functions at
different temperatures on EGR, EFE, AIR Management
Systems and transmission converter clutch.
• To provide a switch point for hot temperature light
indication.
• To vary spark advance.
Pressure Sensors
All engine families use various types of pressure sensors
except 3.8L (RPO LC3). The ECM uses sensor voltage
information to adjust air/fuel ratio and/or spark timing or
transmission converter clutch.
Barometric Pressure (BARO) Sensor
The BARO sensor is located in the engine
companment. It produces a voltage of 3 to 4.5 volts to
indicate the ambient (barometric) air pressure. The BARO
sensor is not used on all engine applications. The output
varies with altitude.
Manifold Absolute Pressure (MAP) Sensor or
Vacuum Sensor
The MAP Sensor or Vacuum Sensor is mounted in the
engine compartment. This sensor measures changes in
manifold pressure and provides this information (electrical
signal) to the ECM. The pressure changes reflect need for
adjustment in air/fuel mixture and spark timing (EST) that
are required to maintain good vehicle performance under
various driving conditions.
FUEL CONTROL SYSTEM (FIG. 6E1-4)
Mixture Control Solenoid (Figs. 6E1-5 and 6)
The fuel flow through the carburetor idle main
metering circuits is controlled by a mixture control (M/C)
solenoid located in the carburetor. The M/C solenoid
changes the air/fuel mixture to the engine by allowing more
or less fuel to flow through the carburetor. The ECM
controls the M/C solenoid by providing a ground for the
solnoid. When the solenoid is energized, the fuel flow
through the carburetor is reduced, providing a leaner fuel
mixture. When the ECM removes the ground path, the
solenoid de-energizes and allows more fuel flow and thus
a richer mixture. The solenoid js turned on and off at a rate
of 10 times per second.
Oxygen Sensor (Fig. 6E1—7)
The oxygen sensor is mounted in the engine stream. It
supplies a low voltage (under 1.2 volt) when the fuel mixture
is 'lean and a higher voltage.(up to 1 volt) when the fuel
mixture is rich. The oxygen sensor supplies a voltage when
the exhaust stream has reached 360°C (600°F). On some
installations, it may cool off at idle and the system will then
go to open loop. Running at fast idle will warm up the
sensor.
The oxygen sensor requires the use of unleaded fuel
only.
System Operation
The ECM determines the proper fuel mixture by
monitoring the signal sent by the oxygen sensor. When
mixture is lean to oxygen sensor, a low voltage signal is sent
to the ECM and the ECM commands (dwell output signal)
a richer mixture to the M/C solenoid. When the mixture
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6EJ-4 COMPUTER COMMAND CONTROL
12
ENGINE CONDITION
STARTING (CRANKING)
WARM-UP
WARM OPERATION
IDLE AND CRUISING
("CONSTANT" ENGINE
SPEED)
ACCELERATION AND
DECELERATION ("CHANGING"
ENGINE SPEEDS)
WIDE-OPEN THROTTLE
FUEL CONTROL SYST
INPUTS TO ECM
• TACHOMETER LESS THAN
200 RPM
• TACH ABOVE 200 PPM
(ENGINE RUNNING)
» O2 SENSOR LESS THAN
1030°C(600°F)
• COOLANT LESS THAN
150°F (66°F)
• LESS THAN 1 0 SECONDS
ELAPSED SINCE STARTING
• O2 SENSOR ABOVE
1030°C(600°C)
• COOLANT ABOVE
150°C (66°F)
• MAP SENSOR
• THROTTLE POSITION
SENSOR (TPS)
• MAP SENSOR
» 02 SENSOR
• TPS FULLY OPEN
• MAP SENSOR
EM OPERATION
M/C SOLENOID OPERATION
M/C SOLENOID OFF
(RICH MIXTURE)
FIXED COMMAND
FROM ECM TO
M/C SOLENOID
M/C SOLENOID SIGNAL
DETERMINED BY
OXYGEN SENSOR
INFORMATION
TO ECM
MOMENTARY PROGRAMMED
SIGNAL FROM ECM DURING
PERIOD AFTER THROTTLE
CHANGE UNTIL OXYGEN
SENSOR RESUMES CONTROL
OF M/C SOLENOID
VERY RICH COMMAND
TO M/C SOLENOID
DWELLMETER READING
0°
FIXED READING
BETWEEN 10° AND
50°
VARING ANYWHERE
BETWEEN 10° AND
50° (NOMINAL 35°)
(FASTER WITH
HIGHER RPM)
MOMENTARY
CHANGE, CAN'T BE
READ ON
DWELLMETER. WILL
BE VARYING, BUT
HIGH OR LOW ON
SCALE DEPENDING
UPON OPERATING
CONDITION(S|
. 6°
208857
Fig. 6E1-4—Fuel Control System
is rich to the oxygen sensor, a high voltage signal is sent to
the ECM and the ECM commands a leaner mixture to the
M/C solenoid.
When car is started, there is a short delay which sends
a rich only signal from the ECM to the M/C solenoid. The
delay time is dependant upon coolant temperature. During
engine warm-up and before oxygen sensor has reached
operating temperature, the ECM sends a fixed mixture
command to the M/C solenoid. This is called Open Loop.
When engine and oxygen sensor have reached
operating temperature and a predetermined time has
elapsed in the ECM, the ECM monitors the voltage output
of the oxygen sensor and generates a dwell output signal
(also called duty cycle) to the M/C solenoid. This is called
Closed Loop. (Fig. 6E1-S). When the system in open or
closed loop modes tnd the throttle is opened to near
W.O.T., the ECM sends a steady power enrichment
command 10 ;he M/C solenoid.
Most all of the following components are used on a
given er.gine:
THROTTLE POSITION SENSOR (TPS)
The TPS (Fig. 6EI-Q) is mounted in the carburetor
body, li is moved by the accelerator pump linkage. It •
provide;, a ICVA voltage (under 1 volt) when the throttle
blades art closed and up to 5 volts as the throttle blades are
opened 10 viidc open throttle. The ECM needs this voltage
;o indicate 'hrottle petition.
IDLE SPEED CONTROL (ISC)
An Idle Speed Control (ISC) system (Fig. 6E1-10) is
used on some engines to control id|e speed. ISC maintains
low idle speeds while preventing stalls due to engine load
changes. A motor assembly mounted on the carburetor
moves the throttle lever to open or close the throttle blades.
The ECM monitors engine load to determine proper
idle speed. To prevent stalling, the ECM monitors the air
conditioning compressor switch, transmission, part/neutral
switch, and the ISC throttle switch. With this information,
the ECM will control the ISC motor and vary the engine
idle RPM as necessary.
ISC THROTTLE SWITCH
The ISC switch is mounted in the ISC motor housing.
It is closed when the throttle lever contacts the ISC plunger
and opens as the throttle lever moves away from {he
plunger.
AIR CONDITIONING "ON" SWITCH
When A/C is turned "on", a switch in the compressor
is supplied 12 volts to engage the compressor. At the same
time, the ECM, because of changes in engine load, adjusts
ISC to maintain idle speed.
ELECTRONIC SPARK TIMING (EST)
Electronic Spark Timing (EST) is used on all eneines
except 3.SL (RPO LC3). The EST distributor (Fig. 6EJ"-I 1)
contains no vacuum or centrifugal advance and uses a
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13
VITON TIP
ON PLUNGER
SPRING
STAINLESS STEEl
CASKET
CARBURETOR
, -BRASS LOCATOR
I S FOR -O" RING
••O" RING
Fig. 6E1-5—M/C Solenoid-E2SE
IDLE AIR BLEED VALVE
MAIN METERING ROD.
MIXTURE CONTROL SOLENOID
LEADS FROM ELECTRONIC
CONTROL MODULE
IK-UKf WUUIOt
Mnu nwiiut.
VUCMEkOOT
Fig. 6E1-7—Oxygen Sensor
seven-terminal HEI module. It has four wires going to a
four terminal connector in addition to the connectors
normally found on HEI distributors. A reference pulse,
indicating both engine RPM and crankshaft position, is sent
to the ECM. The ECM determines the proper spark
advance for the engine operating conditions and sends an
"EST" pulse to the distributor.
Under normal operating conditions, the ECM will
control the spark advance. However, under certain
operating conditions such as cranking or when setting base
timing, the distributor can operate without ECM control.
This condition is called BYPASS and is determined by the
bypass lead from the ECM to the distributor. When the
bypass lead is at 5 volts, the ECM will control the spark.
When the bypass line is at ground or open circuited, the HEI
module will control the spark. Disconnecting the 4—terminal
EST connector causes the engine to operate in the bypass
mode.
CLOSED LOOP CYCLE
Fig. 6E1-6—M/C Solenoid-E2ME and E4ME
Fig. 6E 1-8—Closed Loop Cycle
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6E1-6 COMPUTER COMMAND CONTROL
14
yH"!'!"!
Fig. 6E1-9—Throttle Position Sensor
Electronic Spark Control (ESC) and EST
Electronic Spark Control, used with a turbocharged
engine, receives the EST signal from the ECM and
remodifies it when the Electronic Spark Control (ESC)
senses detonation in the engine through its detonation
sensor.
AIR MANAGEMENT
The AIR system helps reduce hydrocarbon (HC) and
carbon monoxide (CO) content in the exhaust gases. It does
this by injecting air into the exhaust ports of each cylinder
during cold engine operation. This air injection also helps
to heat up the catalytic converter. When the engine is warm
or is in closed loop, the AIR system injects air into the
catalytic convener. This helps lower HC and CO in the
exhaust.
THROTTLE
CONTACT
SWITCH
MOTOR
ELECTRONIC SPARK TIMING DISTRIBUTOR
ROTOR
Fig. 6EI-10—Idle Speed Control Motor
Fig. 6E1-1 1—EST Distributor
When the engine is cold, the ECM energizes an AIR
CONTROL solenoid. .This allows air to flow to an AIR
SWITCHING valve. The air switching valve is energized
to direct air to the exhaust ports.
On a warm engine or when in closed bop, the ECM
de^energizes the air switching valve, directing air to the
converter.
If the air control valve detects a rapid increase in
manifold vacuum (as under a decel), certain operating
modes, or the ECM self-diagnostic system detects any
failure in the system, air is diverted to the air cleaner.
EXHAUST GAS RECIRCULATION (EGR)
The ECM controls the ported vacuum to the EGR
valve with a solenoid valve. When the engine is cold, the
solenoid valve is energized and blocks vacuum to the EGR
valve. When the engine is warm, the solenoid valve is de-
energized and EGR is allowed.
EVAPORATIVE EMISSION CONTROL SYSTEM
The ECM controls the vacuum to the purge valve in
the charcoal canister with a solenoid valve. When the
system is in open loop, the solenoid valve is energized and
blocks vacuum to the purge valve. When the system is in
closed loop, above specified RPM, the solenoid valve is de-
energized and vacuum can be applied to the purge valve.
This releases the collected vapors into the intake manifold.
EARLY FUEL EVAPORATION (EFE)
TWO types of EFE systems are controlled by the ECM:
One EFE system uses a valve and actuator motor that
controls a valve assembly and has an ECM controlled
solenoid located in the vacuum source to the valve motor.
The function of the solenoid is to control the shut offof the
system by an electrical signal supplied by the ECM.
-------
15
COMPUTER COMMAND CONTROL 6E1-7
The other EFE system, used in a 1.6L engine, has a
ceramic heater grid located underneath the primary bore of
the carburetor which is part of the insulator. When the
icnition switch is turned "on" and engine coolant
temperature is low, voltage is applied to the EFE relay
through the ECM. With the EFE relay energized, voltage
is applied to the EFE heater.When coolant temperature
increases, the ECM de-energizes the relay which shuts "off"
EFE heater.
TRANSMISSION CONVERTER CLUTCH (TCC)
The ECM controls a solenoid mounted in the
automatic transmission. When the vehicle speed is high
enough, the ECM energizes the solenoid and allows the
torque converter to mechanically couple the engine to the
transmission. When operating conditions indicate the
transmission should operate as a normal fluid coupled
transmission, the solenoid is de-energized. The transmission
also returns to normal automatic operation when the brake
is depressed.
Vehicle Speed Sensor (VSS)
The VSS is mounted behind the speedometer in the
instrument cluster. It provides a series of 8-volt pulse used
to determine vehicle speed.
High Gear Switch
The high gear switch is mounted in the transmission.
It opens when the transmission has shifted into high gear
and closes under any other condition. •
Park/Neutral (P/N) Switch
The P/N switch is connected to the transmission gear
selector. It is closed when the selector is in park or neutral,
and is open when the selector is in gear.
WIRING HARNESS AND CONNECTORS
The wiring harnesses for the system electrically
connects the ECM to the various switches and sensors
within the system. The wiring is an additional harness in
the engine compartment and connects to the ECM located
inside the car.
There are many new components required for the
system. This includes new terminals, connectors, cables and
seals. All of the connectors will have positive locks and and
secondary terminal locks.
AH system connections in the engine compartment will
be environmentally protected. The reasons for using this
type of connection are low voltage and current levels, and
the environment to which the connectors are exposed. In
many cases in the system, the voltage is limited to 5V and
as low as 500 MV for the oxygen sensor connections. In
nearly all cases, the current is below 250 MA.
Environmental protection protects the terminations
from the harsh corrosive engine compartment environment.
This is especially important when the voltage and current
levels are too low to break down oxidation and film growth
on the terminals, as in the case for the Computer Command
Control system.
DIAGNOSIS
GENERAL
The Computer Command Control system has a self-
diagnostic system which will cause the "CHECK
ENGINE" lamp on the instrument panel to remain "on"
when engine is running. This is an indication that there is
a fault in the system. If this is the problem, refer to the
Diagnostic Circuit Check chart (Fig. 6E1-14).
Before suspecting a problem in the Computer
Command Control system and it is not "CHECK
ENGINE' lamp related, refer to Section 6 "Engine
Performance Diagnosis" in companion manual.
The Computer Command Control system diagnosis
starts in sequence with the following charts:
1. Diagnostic Circuit Check chart
2. Driver Complaint
3. System Performance Check chart
It is important that these charts be followed in a step—
by-step sequential procedure without leaving out a step'or
.assuming the solution to the problem. If charts are not
followed, the system will be improperly diagnosed.
-------
6E1-8 COMPUTER COMMAND CONTROL
16
|l. Diagnottic Circu'n Chrck I
2. Driver Cofnpl»iot Sheel
[ 3. - System P«rformahc« Chech |
|No Trouble Found]
[Syrtem Performance Check |
Fig. 6E1-12—Computer Command Control Diagnostic Procedure
Although there are many charts and trouble codes
connected with the system diagnostics, only two charts are
needed to prove the system is properly operating. Normally,
only three charts, are needed to diagnose and repair a
problem.
Figure 6E1-12 summarizes the system diagnosis
procedure.
TOOLS AND EQUIPMENT
The Computer Command Control system requires the
following tools and equipment (Fig. 6E1-13) to properly
diagnose a complete system:
!. System Performance Checking
• Tachometer-Either a harmonic balance revolution
pickup type or electronic coil trigger signal pickup type
tachometers can be used for diagnosis.
• Dwellmeter - Used to indicate the performance
condkionsof the M/C solenoid circuit. Connect the positive
lead of dwellmeter to the bright green connector in the
••virinj harness near the M/C solenoid. Place meter on 6-
cylincer scale. The scale on the meter will show the
condi:ion of the M/C solenoid circuit. When needle is on
10"' scale, this indicates a rich mixture. A lean mixiture will
read near 54° scale. A varying needle indicates that the
system is in closed loop.
• Vacuum Gage -to monitor manifold engine vacuum
• • Vacuum Pump - to check pressure or vacuum sensors
and vacuum operated valves (EGR, AIR. etc.)
2. Circuit Checking
• Voltmeter and Ohmmeter - use digital volt-
chmrne:er J-29125 to measure voltage and ohm for
Cernpi.:er Command Control circuits
* jjmper Wires - to by-pass a circuit and to insert
between special connectors to permit access to the connector
terminals for circuit checking.
» Test light
• Connsctor Tools - Use tool J-28742 for removal of
terrnir.jls on Wither Pack connectors. Refer to Figure
6E1-13 for tool 10 extract terminal from connectors at the
ECM.
DIAGNOSTIC CIRCUIT CHECK
The Diagnostic Circuit Check (Fig. 6E1-14) makes
• sure that the self-diagnostic system works, determines that
the trouble codes will display and guides diagnosis to other
problem areas.
With the engine running and a problem developes in
the system, the "CHECK ENGINE," lamp will come "on"
and a trouble code will be stored in the ECM "Trouble Code
Memory'." The lamp will remain "on" with engine running
as long as there is a problem. If the problem is intermittent,
the "CHECK ENGINE" lamp will go out but the trouble
code will be stored in the ECM trouble code memory.
With ignition turned "ON" and engine stopped, the
"CHECK ENGINE" lamp should be "ON1. This is a bulb
check to indicate that the lamp is working.
The trouble code "test' terminal (Fig. 6E1-14) is
located in a five (5) terminal connector, located under the
dash. A ground terminal is located next to the test terminal.
With the ignition "ON", ground the test terminal.
The "CHECK ENGINE" light will begin to flash a
Trouble Code "12". Code 12 consists of one flash, a short
pause, then two flashes. There will be a longer pause and
Code 12 will repeat two more times. This check indicates
that the self-diagnostic system is working. The cycle will
then repeat itself until the engine is started or the ignition
is turned "OFF." If more than one fault is stored in
memory, the lowest number code will flash three times
followed by the next highest code number, until all faults
have been flashed. The faults will then repeat in the same
order. Remove ground from test terminal before starting
engine..
A trouble code indicates a problem in a given cir-
cuit i.e., trouble code 14 indicates a problem in the
coolant sensor circuit. This includes the coolant sensor.
connector, harness, and Electronic Control Module
(ECM). The procedure for finding the problem'can be
found in Diagnosis Trouble Code Chart 14. Charts are
provided for each trouble code.
-------
17
COMPUTER COMMAiMu
J-29125'
DIGITAL
VOLT/OHMMETER
(10 MEGOHM
INPUT IMPEDANCE.
MINIMUM)
C-4 SYSTEEVl TESTING TOOLS
DWELL/TACHMETER
(IF ENGINE PERFORMANCE
CHANGES WHEN DWELL
METER IS CONNECTED,
FT CAN NOT BE USED FOR
DIAGNOSTICS OF C-4)
VACUUM PUMP
(20 IN. HG.
MINIMUM)
POWERED
TEST LIGHT
UNPOWERED
TEST LIGHT
JUMPER
WIRES—APPROX. 6" LONG
' 1 - FEMALE BOTH ENDS
11-MALE BOTH ENDS
- MALE-FEMALE
ON OPPOSITE ENDS
(TERMINAL NOS.
12014836 AND 12t>14837.
MAKE JUMPERS UP WITH
#16,18 OH 20 WIRE.)
1.2MM
(.05 IN.)
Irl
L. 1.7MM
ar(.07IN.)
CONNECTOR PIN
EXTRACTION TOOLS
Fig. 6E1-13—Tools and Equipment
When the engine is started, the "CHECK ENGINE"
lieht will remain "ON" for 1 to 4 seconds and then go
'OFF. If the "CHECK ENGINE" light remains ON, the
self-diagnostic system has detected a fault.
If a trouble code can be obtained when the 'CHECK
ENGINE" light is OFF with the engine running, the trouble
code must be evaluated. A determination must be made to
see if the fault is intermittent or if the engine must be at
certain operating conditions to turn the "CHECK
ENGINE" light ON.
Faults indicated by trouble codes 13, 24, 44 and 45
require engine operation at part throttle for up to five
minutes before the "CHECK ENGINE" light will come on
and store a trouble code.
The fault indicated by trouble code 15 takes five
minutes of engine operation before it will display. The
diagnostic charts for trouble codes 13, 15, 24, 44 and 45
should be used if any of these trouble codes can be obtained.
Clearing Trouble Code Memory
The trouble code memory is fed a continuous 12 volts
even %vith key in "OFF" position. After a fault has been
corrected, it will be necessary to remove this voltage for 1C
seconds to clear any stored codes. Voltage can be removec
by removing "ECM" fuse, removing voltage at battery 01
disconnecting lettered connector at the ECM.
DRIVER COMPLAINT
After performing the Diagnostic Circuit Check zw
there is no "CHECK ENGINE" light with a warm runnin.
engine, then refer to Driver Complaint (Fig. 6E1-15) for a.-
emission non-compliance problem or an engin
performance problem (odor, surge, fuel economy...)-
-------
£51-10 COMPUTER COMMAND CONTROL 18
DIAGNOSTIC CIRCUIT CHECK
Always check "PROM" for correct application before replacing an "ECM.
"Test." Ground
Term.
• Key "ON." engine stopped, "test" term, ungrounded.
• Note "Check Engine" light.
B| c |D
UBhtOPF,
I See Chart 5=4 |
I Does not flash code 12 [
S*e Chart =7
Code 51
Check that all PROM pins
are fully seated in socket.
If OK, replace PROM.
[ Light "OFF" |
Refer to the additional
codes recorded above.
j No additional codes
[ Additional codesj
r
| All others I | Codes 13. 15, 24, 44. 45, 55 [
Trouble is intermittent so code charts
cannot be used. Make physical check of
circuit indicated by trouble code.
See driver complaints on
following page.
"See Code(s) Clearing Procedure
The system performance check should be performed after any
repairs to the "System" have been made.
Light "ON"J
Ground "test" term, and
note "Check Engine" light.
I Flashes Code 12 ]
| Note and record any additional codes. |
| No Code 51
• Turn ignition "OFf."
• Clear codes.*
• Remove "test" term, ground.
• Set parking brake with trans, in "PARK"
(A.T.). "NEUTRAL" (M.T.), and block
drive wheels.
• Run warm engine at specified idle for two (2)
minutes and note "Check Engine" light.
| Light ''ON'7"]
[ Ground "test" term, and note codes.]
See applicable Trouble Code Chart(s).
If more than one code is stored, start with
lowest code unless one is 50 series, then
start with it. For code 52 or 53, replace
ECM. Leave "test" term, grounded while
using charts unless otherwise instructed.
203798
Fig. 6E1-14—Diagnostic Circuit Check
-------
19
COMPUTER COMMAND CONTROL 6E-1-21
TROUBLE CODE IDENTIFICATION
The "CHECK ENGINE" light will only be "ON" if the malfunction exists under the
conditions listed below. It takes up to five seconds minimum for the light to come on
when a problem occurs. If the malfunction clears, the light will go out and a trouble
code will be set in the ECM. Code 12 does not store in memory. .If the light comes "on"
intermittently, but no code is stored, go to the ''Driver Comments" section. Any codes
stored will be erased if no problem reoccurs within 50 engine starts.
The trouble codes indicate problems as follows:
TROUBLE CODE 12
TROUBLE CODE 13
TROUBLE CODE 14
TROUBLE CODE 15
TROUBLE CODE 21
TROUBLE CODE 23
TROUBLE CODE 24
TROUBLE CODE 32
TROUBLE CODE 34
No reference pulses to the
ECM. This code is not
stored in memory and will
only flash while the fault
is present.
Oxygen Sensor Circuit - The
engine must run up to five
minutes at part throttle,
under road load, before this
code will set.
Shorted coolant sensor cir-
cuit • The engine must run
up to two minutes before
this code will set.
Open coolant sensor circuit
- The engine must run up
to five minutes before this
code will set
Throttle position sensor cir-
cuit - The engine must run
up to 25 seconds, below
800 RPM, before this code
will set.
Open or grounded M/C
solenoid circuit.
Vehicle speed sensor (VSS)
circuit - The car must
operate up to five minutes
at road speed before this
code will set.
Barometric pressure sensor
(BARO) circuit low.
Manifold absolute pressure
(MAP) or vacuum sensor
TROUBLE CODE 35
TROUBLE CODE 42
TROUBLE CODE 44
TROUBLE CODE 44
&45
TROUBLE CODE 45
TROUBLE CODE 51
TROUBLE CODE 52
TROUBLE CODE 53
TROUBLE CODE 54
TROUBLE CODE 55
circuit - The engine must
run up to five minutes,
below 800 RPM, before
this code will set.
Idle speed control (ISC)
switch circuit shorted. (Over
50% throttle for over 2 sec.)
Electronic spark timing (EST)
bypass circuit grounded.
Lean oxygen sensor indica-
tion - The engine must
run up to five minutes,
in closed loop, at part
throttle and road load before
this code will set.
(At same time) - Faulty
oxygen sensor circuit.
Rich System indication -
The engine must run up to
five minutes, in closed loop ,
at part throttle and road load
before this code will set.
Faulty calibration unit
(PROM) or installation. It
takes up to 30 seconds
before this code will set.
Faulty ECM
Faulty ECM
Shorted M/C solenoid
circuit.
Grounded +8 volts, Vref,
faulty oxygen sensor or
ECM.
Fig. 6E1-24—Trouble Code Identification
-------
20
COMPUTER COMMAND CONTROL 6E1-75
Fig. 6E 1-89—Wiring Diagram-5.0L/5.7L Engine
-------
21
6E1-76 COMPUTER COMMAND CONTROL
GLOSSARY OF TERMS
A F — Air fuel
AIR — Air injection Reactor
AIR INJECTION REACTOR (AIR) SYSTEM — air flow from pump is
directed by system controlled solenoids to reduce exhaust emissions.
BAROMETRJC ABSOLUTE PRESSURE SENSOR (BARO) —Reads
atmospheric pressure. May be called BARO, or barometric absolute pres-
sure sensor.
CAR INERTIA WEIGHT CLASS— Weight of car: used in exhaust emis-
sion tests to determine inertia weight settings for the chassis dynamometer.
This information is used to calibrate the engine calibration unit (PROMl.
CARBON MONOXIDE (CO) — One of the poButaius found in engine
exhaust.
CATALYTIC CONVERTER, THREE-WAY — Exhaust convener con-
taining platinum and palladium to speed up conversions of HC and CO, and
rhodium to accelerate conversion of NOx.
CONTROLLED CANISTER PURGE (CCP)— ECM controlled solenoid
valve that permits manifold vacuum to purge the evaporative emissions from
the charcoal canister.
CLOSE D LOO P CA RBURETO R CONTROL—Used to describe oxygen
sensor to ECM to M/C solenoid circuit operation.
COOLANT TEMPERATURE SENSOR — Device that senses the engine
coolant temperature, and passes thai information to the electronic control
module through a coaxial connector.
DIAGNOSTIC CODE—Pair of numbers obtained from flashing "CHECK
ENGINE" tight. This code can be used; to determine area in the system
where a malfunction may be located.
DWELL — The amoum of time (recorded on a dwellmeter in degrees of
crankshaft rotation) thai voltage passes through a closed switch: for example.
ignition contact points or internal switch in an electronic control module.
EARLY FUEL EVAPORATION IEEE) — Method of warming the intake
manifold during cold engine operation. Provides efficient air/fuel mixing.
EXHAUST GAS RECIRCULATION (EGR) — Method of reducing NOx
emission levels. . •
ELECTRONIC CONTROL MODULE'(ECM) — A metal cased box (lo-
cated in passenger compartment) containing electronic circuitry which oper-
a:ej the system, and rums on the "CHECK ENGINE" light when a malfunc-
tion occurs in the system. Service replacement name is engine control
module assembly, or "controller, carb."
EMR — Electronic Module Retard. Controls spark retard.
ENERGIZEDE-ENERGIZE — When'voltage is passed through the MC
solenoid, the metering'control armature'is pulled into the solenoid (ener-
gized). When the voltage to the solenoid is turned off, a spring rais« the
metering control armaiure ide-energized).
ENGINE CALIBRATION UNIT (ECU) — An electronic component
which can be specifically programmed to the design of each car model to
control the M C solenoid. The ECU plugs into the electronic control module
(ECM,. The ECU may be called a PROM.
ELECTRONIC SPARK TIMING (EST) — ECM controlled timing of
ignition spark.
FEDERAL — Car engine available in all states except California.
HIGH IMPEDANCE VOLTMETER — Has high opposition to the flow of
elec;nca! current. Good for reading circuits with low current flow, such as.
found in the svstem.
HYDROCARBONS (HC|—One of the pollutants found in engine exhaust.
IDEAL MIXTURE — The air/fuel ratio which provides the best perform-
ance, while maintaining maximum conversion of exhaust emissions, typi-
cally 14.7/1.
IDLE AIR BLEED VALVE — Controls the amount of air let into the idle
fuel mixture prior to the mixture entering the idle system, when the M/C .
solenoid is energized.
IDLE SPEED CONTROL MOTOR (ISO — Regulates throttle valve posi-
tion. Is controlled by the ECM.
INPUTS—Information from sources(coo!am'tejnperature sensors, exhaust
oxygen sensor, etc.) that tells the ECM how the engine is performing.
INTERMITTENT— Occurs now and then: not continuously. In electrical
circuits, refers to occasional open, short, or ground.
MALFUNCTION — A problem that causes the system to operate incor-
rectly. Typical malfunctions are: wiring harness opens or shorts, failed
sensors or, M/C solenoid or ECU failure.
MANIFOLD PRESSURE SENSOR (MAP) — Reads pressure changes in
intake manifold. May be called MAP, or manifold absolute pressure sensor.
MANIFOLD VACUUM SENSOR — Reads pressure changes in intake
manifold in relation to barometric pressure. May be called manifold.
barometric pressure sensor, or differential sensor.
MIXTURE CONTROL (M'C) SOLENOID — Device, installed in car-
buretor, which regulates the air/fuel ratio.
MODE — A particular stale of operation.
NATIONAL — Car/engine available in all states.
NITROGEN, OXIDES OF (NOx) — One of the pollutants found in engine
exhaust.
OPEN LOOP— Describes ECM control of the M'C solenoid without use of
the oxygen sensor information.
OUTPUT— Functions, typically solenoids, that are controlled by the ECM.
OXYGEN SENSOR. EXHAUST — Device that detects the amount of
oxygen (O..) in the exhaust stream, and sends that information to the ECM.
PROM — Programmable Read Only Memory: an electronic term used to
describe the engine calibration unit lECUt.
SELF-DIAGNOSTIC CODE — The ECM can detect malfunctions in the
system. If a malfunction occurs, the ECM turns on the "CHECK ENGINE"
light. A diagnostic code can be obtained from the ECM through the "Check
Engine" light. This code will indicate the area of the malfunction.
TORQUE CONVERTER CLUTCH (TCC) — ECM controlled solenoids
in transmission which positively couples the transmission to the engine.
THROTTLE POSITION SENSOR (TPSl — Device that tells the ECM
when the throttle position changes.
TV'S— Thermal Vacuum Switch. Used to control vacuum in relationship to
engine temperature.
VACUUM, MANIFOLD — Vacuum source in manifold below throttle
plate.
VACUUM. PORTED— Vacuum source in carburetor above closed throt-
tle plate.
VEHICLE SPEED SENSOR (VSS) — Sensor in speedometer cluster which
sends vehicle speed information to the electronic control module.
Fig. 6E1-90—Glossary of Terms
-------
22
ATTACHMENT 4
Test Vehicle Description
Model/Year
Make
Emission Control System
Engine Configuration
Bore x Stroke
Displacement
Rated Horsepower
Transmission
Chassis Type
Tire Size
Inertial Weight
Vin
AHP
Engine Family
Fuel Type
Compression Ratio
1981
Chevrolet Camero Z-28
EGR, air injection, closed loop, dual bed
catalytic converter
V-8
4.00 inches x 3.48 inches
350.0 cubic inches
155
A-3 lock-up
Sedan
P 225/70 R 15
4000 Ibs.
P87LX BL 103466
8.2
AVA 5.7L 11L4AC
Unleaded - IND HO
8.2:1
-------
ATTACHMENT 5
DILUTE SAMPLE TESTING
Date
Test Numbers
8 Oct. 80
9 Oct. 80
15 Oct. 80
16 Oct. 80
21 Oct. 80
28 Oct. 80
29 Oct. 80
30 Oct. 80
31 Oct. 80
4 Nov. 80
5 Nov. 80
80-6331-32
80-6333-34
80-6335-36
80-6337-38
80-6339-40
80-6344-6625
80-6626-27
80-6628-29
80-6630-31
80-6632-33
80-6634-35
FTP
HC
0.206
0.257
1.083
1.120
1.020
6.289
0.566
6.203
0.220
0.200
0.174
CO
1.40
1.89
31.58
51.96
50.24
209.06
37.13
213.46
1.75
1.64
1.18
C0?
618.
618.
666.
729.
692.
432.
671.
445.
589.
594.
586.
R0»
0.69
0.66
0.22
0.29
0.33
0.24
0.34
0.29
2.57
0.90
0.90
FE
14.3
14.3
12.3
10.9
11.5
11.5
12.1
11.1
15.0
14.8
15.6
HFET
HC
0.64
0.056
0.111
0.248
0.123
2.578
.1.105
2.717
0.267
0.054
0.053
CO
0.02
0.03
18.20
41.74
20.23
112.59
65.53
119.07
7.52
0.01
0.02
CO?
422.
424.
458.
521.
470.
312.
390.
313.
400.
412.
418.
NOx
0.52
0.51
0.26
0.20
0.29
0.15
0.16
0.16
1.14
0.59
0.62
FE
21.0
20.9
18.2
15.1
17.7
17.8
17.9
17.4
21.5
21.5
21.2
Comments
Baseline
Baseline
MCS disconnected*
CTS disconnected*
IPS disconnected*
MCS disconnected
ECO sensor shorted
TPS disconnected
EGO disconnected
Baseline
Baseline
to
U>
* These three test sequences vere run with an open circuit in the air switching solenoid in addition to the listed disablements.
This causes air to be supplied to the catalyst continuously.
-------
ATTACHMENT 6
I/M Testing Before Catalysts
4 Mode Idle
Date
8 Oct.
9 Oct.
15 Oct,
16 Oct,
21 Oct.
28 Oct,
29 Oct,
30 Oct,
31 Oct,
4 Nov.
5 Nov.
80
80
80
80
80
80
80
80
80
80
80
Teat Dumber s
80-6331-32
80-6333-34
80-6335-36
80-6337-38
80-»6339-40
80-6344-6625
80-6626-27
80-6628-29
80-6630-31
80-6632-33
80-6634-35
50 Cruise
HC/CO
90/.45
90/.45
160/5.20
110/5.20
180/6.00
185/6.50
200/6.50
200/6.50
95/.7S
90/.48
95/.60
Idle
HC/CO
100/.10
160/.45
300/5.60
200/4.40
300/5.80
340/6.2
340/6.40
330/5.80
65/.13
150/.42
170/.42
2500
HC/CO
70/.60
80/.45
195/6.40
110/5.40
180/5.80
240/7.70
240/8.00
210/6.80
20/.35
60/.58
70/.50
Idle
HC/CO
160/.45
ISO/. 40
400/6.00
200/4.80
340/6.20
370/6.70
440/6.50
340/6.50
90/.13
140/.60
145/.40
Drive
HC/CO
190/.70
200/.45
325/6.20
230/4.60
340/6.20
350/6.70
340/6.10
360/6.60
100/.18
ISO/. 60
190/.50
Two Mode Loaded
30 MPH
HC/CO
140/.90
130/.80
200/4.60
125/5.60
200/5.60
210/5.60
240/6.80
220/5.70
80/.80
120/.85
140/.80
Idle
HC/CO
170/.50
175/.50
310/6.0
195/4.30
360/6.80
380/6.90
320/6.10
380/6.70
•80/.15
ISO/. 43
160/.41
Comments
Baseline
Baseline
MCS disconnected*
CTS disconnected*
TPS disconnected*
MCS disconnected
ECO sensor shorted
TPS disconnected
- 'ECO disconnected
Baseline
Baseline
'* These- three test sequences were run with an open circuit in the air switching solenoid in addition to the listed disablements.
This causes air to be supplied to the catalyst continuously.
-------
I/M Testing After Catalysts
A Mode Idle
Two Mode Loaded
Date
8 Oct.
9 Oct.
15 Oct,
16 Oct,
21 Oct,
28 Oct,
29 Oct,
30 Oct,
31 Oct,
A Nov.
5 Nov.
80
80
80
80
80
80
80
80
80
80
80
Test Numbers
80-6331-32
80-6333-34
80-6335-36
80-6337-38
80-6339-40
80-6344-6625
80-6626-27
80-6628-29
80-6630-31
80-6632-33
80-6634-35
50 Cruise
HC/CO
30/.02
20/.02
35/.80
20/1.60
30/1.00
180/5.70
190/6.30
200/6.30
40/.15
20/.02
18/.02
Idle
HC/CO
30/.02
30/.02
20/.15
30/.20
20/.05
365/6.30
30/.08
370/6.00
20/.02
30/.02
30/.02
2500
HC/CO
30/.02
30/.02
25/.7S
20/.80
20/.30
270/7.70
230/8.50
260/7.00
20/.02
22/.02
28/.02
Idle
HC/CO
30/.02
30/.02
20/.18
30/.15
30/.06
390/6.80
50/.05
430/6.50
20/.02
18/.02
19/.02
Drive
HC/CO
30/.02
30/.0'2
25/.18
20/.15
20/.20
360/6.60
40/.35
370/6.60
20/.02
16/.02
28/.02
30 MPH
HC/CO
40/.02
30/.02
30.55
30/1.0
40/.30
210/5.60
210/6.20
220/5.00
20/.02
20/.02
30/.02
Idle
IcTco
30/.02
- 40/.05
40/.18
20/.15
20/.08
390/6.90
50/.07
390/6.50
20/.05
19/.02
30/.02
Commentg
Baseline
Baseline
MCS disconnected*
CTS disconnected*
TPS disconnected*
MCS disconnected
ECO sensor shorted
TPS disconnected
EGO disconnected
Baseline
Baseline
to
Ul
* These three test sequences were run with an open circuit in the air switching solenoid in addition to the listed disablements.
This causes air to be supplied to the catalyst continuously.
-------
ATTACHMENT 7
Results of Propane Injection Diagnostic Procedure
1 CFH Propane
Date
Test Numbers
RPM
ICO
8 Oct. 80
9 Oct. 80
15 Oct. 80
16 Oct. 80
21 Oct. 80
23 Oct. 80
29 Oct. 80
30 Oct. 80
31 Oct. 80
4 Nov. 80
5 Nov. 80
80-6331-32
80-6333-34
80-6335-36
80-6337-38
80-6339-40
80-6344-6625
80-6626-27
80-6628-29
80-6630-31
80-6632-33
80-6634-35
850
760
800
630
960
870
950
775
680
720
760
.02
.02
.12
.15
.05
6.3
.05
6.3
.05
.02
.02
7
2
7
7
7
7
1
2
1
3
3
Code
RPM
RPM
ICO
Code
RPM
730
760
850
700
790
620
960
870
1030
765
700
725
740
.02
.02
.17
.20
.08
7.3
.10
7.0
.05
.02
.02
7
2
7
7
7
7
2
1
2
7
2
RPM
850
700
790
620
960
870
950
775
670
715
725
ICO Comments
.02 Baseline
.02 Baseline
.17 MCS disconnected*
.15 CTS disconnected*
.05 TPS disconnected*
6.4 MCS disconnected
.05 EGO sensor shorted
6.2 TPS disconnected
.05 EGO disconnected
.02 Baseline
.02 Baseline
* The«e three test -sequences were run with an open circuit in the air switching solenoid in-addition to the li-sted disablements.
This causes air to be supplied to the catalyst continuously.
-------
2 CFH Propane
Date
Test Number!
RPM
ICO
8 Oct. 80
9 Oct. 80
15 Oct. 80
16 Oct. 80
21 Oct. 80
23 Oct. 80
29 Oct. 80
30 Oct. 80
31 Oct. 80
4 Nov. 80
5 Nov. 80
80-6331-32
80-6333-34
80-6335-36
80-6337-38
80-6339-40
80-6344-6625
80-6626-27
80-6628-29
80-6630-31
80-6632-33
80-6634-35
850
720
800
630
960 '
870
950
835
680
730
740
.02
.02
.13
.12
.05
6.4
-
6.7
.04
.02
.02
7
4
7
7
4
7
1
2
1
3
3
Code
RPM
RPM
ICO
Code
RPM
RPM
ICO
600
700
750
750
850
720
790
620
960
870
980
760
710
730
715
.02
.02
.20
.20
.08
7.7
.20
7.4
.04
.02
.02
7
4
7
7
4
7
7
1
2
4
4
680
760
715
700
850
720
790
620
960
870
980
770
675
720
720
.02
.02
.15
.14
.05
6.6
,04
6.5
.04
.02
.02
Comments
Baseline
Baseline
MCS disconnected*
CTS disconnected*
TPS disconnected*
MCS disconnected
ECO sensor shorted
TPS disconnected
ECO disconnected
Baseline
Baseline
to
* These three test sequences were run with an open circuit in the air switching solenoid in addition to the listed disablements.
This causes air to be supplied to the catalyst continuously.
-------
3 CPH Propane
Date
Teat Numberi
RPH
ICO
Code
RFH
RPM
ICO
Code
8 Oct. 80
9 Oct. 80
15 Oct. 80
16 Oct. 80
21 Oct. 80
23 Oct. 80
29 Oct. 80
30 Oct. 80
31 Oct. 80
4 Nov. 80
5 Nov. 80
80-6331-32
80-6333-34
80-6335-36
80-6337-38
80-6339-40
80-6344-6625
80-6626-27
80-6628-29
80-6630-31
80-6632-33
8p-6634-35
850
720
860
640
960
870
980
830
685
740
740
.02
.02
.12
.12
.05
6.7
.04
6.7
.04
.02
.02
7
4
2
7
4
2
-
2
1
3
3
680
740
745
770
850
700
790
620
940
850
745
740
725
730
.02
.02
.25
.20
.09
8.0
7.5
.04
.02
.02
7
4
7
7
7
1
1
2
4
4
RPM
640
RPM
ICO
720
710
850
700
790
620
960
870
775
675
725
730
.02
.02
.15
.15
.05
6.7
6.7
.04
.02
.02
Comments
Baseline
Baseline
MCS disconnected*
CTS disconnected*
TPS disconnected*
MCS disconnected
ECO sensor shorted
TPS disconnected
EGO disconnected
Baseline
Baseline
NO
CD
Note: Propane test was aborted for
test numbers 80-6626-27 at 3 CFH
due to equipment failure.
* These three test sequences were run with an open circuit in the air switching solenoid in addition to the listed disablements.
This causes air to be supplied to the catalyst continuously.
-------
4 CFH Propane
Date
Teat Numbers
RPM
ICO
Code
RFM
RPM
ICO
Code
RPM
RPM
ICO
8 Oct. 80
9 Oct. 80
15 Oct. 80
16 Oct. 80
21 Oct. 80
23 Oct. 80
29 Oct. 80
30 Oct. 80
31 Oct. 80
4 Nov. 80
5 Nov. 80
80-6331-32
80-6333-34
80-6335-36
80-6337-38
80-6339-40
80-6344-6625
80-6626-27
80-6628-29
80-6630-31
80-6632-33
80-6634-35
850
720
790
640
960
870
-
765
675
735
735
.02
,02
.13
.12
.05
6.7
-
6.8
.04
.02
.02
7
4
2
7
4
2
-
2
1
3
3
850
580 720
750
620
540 900
840
-
720
740
775 715
770 735
.02
.02
.20
.18
.09
8.2
-
8.2
.04
.02
.02
7
4
1
7
4
1
—
1
2
4
4
680
760 .
670
690
850
700
790
620
940
870
755
675
720
720
.02
.02
.15
.15
.05
6.7
6.5
.04
.02
.02
Commenta
Baseline
Baseline
MCS disconnected*
CTS disconnected*
TPS disconnected*
MCS disconnected
ECO sensor shorted
TPS disconnected
EGO disconnected
Baseline
Baseline
* These three test sequences were run with an open circuit in the air switching solenoid in addition to the listed disablements.
This causes air to-be-supplied to the catalyst continuously.
-------
ATTACHMENT 8
Results of On-Board Diagnostic Check
Date
Test Numbers
8 Oct. 80
9 Oct. 80
15 Oct. 80
16 Oct. 80
21 Oct. 80
23 Oct. 80
29 Oct. 80
30 Oct. 80
31 Oct. 80
4 Nov. 80
5 Nov. 80
80-6331-32
80-6333-34
80-6335-36
80-6337-38
80-6339-40
80-6344-6625
80-6626-27
80-6628-29
80-6630-31
80-6632-33
80-6634-35
Trouble Codes Output
No test
No teat
12-23-45
12-15
12-21
12-23-45
12-44
12-21
12-13
12
12
Trouble Code Identification
12 * System operational verification
23 " M/C solenoid, 45 " rich system
15 " Open coolant sensor circuit
21 — Throttle position sensor circuit
23 - M/C solenoi^, 45 «• rich system
44 = Lean oxygen sensor
21 = Throttle position sensor
13 •= Oxygen sensor circuit
Comment s
Base1ine
Baseline
MCS disconnected*
CTS disconnected*
TPS disconnected*
MCS disconnected
ECO sensor shorted
TPS disconnected
ECO disconnected
Baseline
Baseline
OJ
o
* These three test sequences were run with an open circuit in the air switching solenoid in addition to the listed disablements.
This causes air to be supplied to the catalyst continuously.
------- |