CHEVROLET CAMARO 1982 Repair Guide

GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 571

Fig. 1: Exploded view of a vacuum servo EFE valve assembly
ELECTRICAL TYPE 1. Remove the air cleaner and disconnect the negative battery cable.
2. Tag, then disengage all electrical, vacuum and fuel connections from the
carburetor.
3. Disconnect the EFE heat er electrical lead.
4. Remove the carburetor.
5. Lift off the EFE heater grid.
To install: 6. Position the EFE heater grid onto the manifold.
7. Install the carburetor.
8. Connect the EFE heater electrical lead.

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9. Connect all electrical, vacuum and f
uel connection to the carburetor.
10. Install the air cleaner and connec t the negative battery cable.

Fig. 2: Electric EFE heater assembly
ELECTRIC EFE RELAY 1. Disconnect the negative battery cable.
2. Remove the retaining bracket.
3. Tag and disconnect all el ectrical connections.
4. Unscrew the retaining bolts and remove the relay.
To install: 5. Position the relay into place and secu re the relay with the retaining bolt.
6. Attach all electrical connections.

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7. Install the retaining bracket.
8. Connect the negative battery cable.
ELECTRONIC ENGINE CONTROLS

COMPUTER COMMAND CO NTROL (CCC) SYSTEM
The Computer Command Control (CCC) Sy stem is an electronically controlled
exhaust emission system that can m onitor and control a large number of
interrelated emission cont rol systems. It can monitor various engine/vehicle
operating conditions and then use this in formation to control multiple engine
related systems. The CCC syst em is thereby making constant adjustments to
maintain optimum vehicle performance und er all normal driving conditions while
at the same time allowing the catalyti c converter to effectively control the
emissions of HC, CO and NO
x.
OPERATION
The Electronic Control Module (ECM) is required to maintain the exhaust
emissions at acceptable le vels. The module is a sma ll, solid state computer
which receives signals from many source s and sensors; it uses these data to
make judgements about operating conditions and then control output signals to
the fuel and emission systems to ma tch the current requirements.
Inputs are received from m any sources to form a complete picture of engine
operating conditions. Some inputs are simp ly Yes or No messages, such as that
from the Park/Neutral switch; the vehicle is either in gear or in Park/Neutral;
there are no other choices. Other data is sent in quantitative input, such as
engine rpm or coolant temperature. T he ECM is pre-programmed to recognize
acceptable ranges or combinations of si gnals and control the outputs to control
emissions while providing good driv eability and economy. The ECM also
monitors some output circuits, making sure that the components function as
commanded. For proper engine oper ation, it is essential that all input and output
components function properly and comm unicate properly with the ECM.
Since the control module is programmed to recognize the presence and value
of electrical inputs, it will also note the lack of a signal or a radical change in
values. It will, for example, react to the loss of signal from the vehicle speed
sensor or note that engine coolant temperature has risen beyond acceptable
(programmed) limits. Once a fault is recognized, a numeric code is assigned
and held in memory. The SERVICE ENGIN E SOON Malfunction Indicator Lamp
(MIL), will illuminate to advise the operator that the system has detected a fault.
More than one code may be stored. Although not every engine uses every
code, possible codes range from 12-999. Additionally, the same code may carry
different meanings relative to each engine or engine family. For example, on the
3.3L (VIN N) engine, code 46 indicates a fault found in the power steering
pressure switch circuit. The same code on the 5.7L (VIN F) engine indicates a
fault in the VATS anti-theft system.

GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 574
In the event of an ECM failure, the system
will default to a pre-programmed set
of values. These are compromise values which allow the engine to operate,
although possibly at reduced e fficiency. This is variously known as the default,
limp-in/limp-home or back-up mode. Driveability is almost always affected when
the ECM enters this mode.

Fig. 1: Computer Co mmand Control schematic

GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 575

Fig. 2: Electronic Control Module (ECM)
LEARNING ABILITY
The ECM can compensate for minor variations within the fuel system through
the block learn and fuel in tegrator systems. The fuel integrator monitors the
oxygen sensor output voltage, adding or subtracting fuel to drive the mixture
rich or lean as needed to reach the ideal air fuel ratio of 14.7:1. The integrator
values may be read with a scan tool; the display will range from 0-255 and
should center on 128 if the oxygen sens or is indicating a 14.7:1 mixture.

Fig. 3: Among other features, a scan tool combines many standard testers into
a single device for quick and accurate diagnosis

GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 576
The temporary nature
of the integrator's control is expanded by the block learn
function. The name is derived from the fact that the entire engine operating
range (load vs. rpm) is divided into sect ions or blocks. Within each memory
block is stored the correct fuel delivery value for that combination of load and
engine speed. Once the operating range enters a certain block, that stored
value controls the fuel delivery unless th e integrator steps in to change it. If
changes are made by the integrator, t he new value is memorized and stored
within the block. As the block learn makes the correction, the integrator
correction will be reduced until the integrator returns to 128; the block learn then
controls the fuel delivery with the new value.

Fig. 4: Inexpensive scan tools, such as this Auto Xray®, are available to
interface with your General Motors vehicle
The next time the engine operates within the block's range, the new value will
be used. The block learn data can also be read by a scan tool; the range is the
same as the integrator and should also center on 128. In this way, the systems
can compensate for engine wear, small air or vacuum leaks or reduced
combustion.
Any time the battery is disconnected, the block learn values are lost and must
be relearned by the ECM. This loss of corrected values may be noticed as a
significant change in driveab ility. To re-teach the system, make certain the
engine is fully warmed up. Drive the v ehicle at part throttle using moderate
acceleration and idle until normal performance is felt.

GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 577
MALFUNCTION INDICATOR LAMP
The primary function of the MIL is to adv
ise the operator and the technician that
a fault is detected, and, in most cases, a code is stored. Under normal
conditions, the malfunction indicator la mp will illuminate when the ignition is
turned ON. Once the engine is started and running, the ECM will perform a
system check and extinguish the lamp if no fault is found.
Additionally, the lamp can be used to retrieve stored codes after the system is
placed in the Diagnostic Mode. Codes ar e transmitted as a series of flashes
with short or long pauses. When the syst em is placed in the Field Service
Mode, the dash lamp will indicate open loop or closed loop function to the
technician.
INTERMITTENTS
If a fault occurs intermittently, such as a loose connector pin breaking contact
as the vehicle hits a bump, the ECM will note the fault as it occurs and energize
the dash warning lamp. If the problem se lf-corrects, as with the terminal pin
again making contact, the dash lamp will extinguish after 10 seconds but\
a code
will remain stored in the ECM memory.
When an unexpected code appe ars during diagnostics, it may have been set
during an intermittent failure that self-c orrected; the codes are still useful in
diagnosis and should not be discounted.
OXYGEN SENSOR
OPERATION
An oxygen sensor is used on all models. The sensor protrudes into the exhaust
stream and monitors the oxygen content of the exhaust gases. The difference
between the oxygen content of the exhaust gases and that of the outside air
generates a voltage si gnal to the ECM. The ECM monitors this voltage and,
depending upon the value of the signal rece ived, issues a command to adjust
for a rich or a lean condition.
No attempt should ever be made to meas ure the voltage output of the sensor.
The current drain of any conventional vo ltmeter would be such that it would
permanently damage the sensor.

GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 578

Fig. 1: Cutaway view of a single-wire oxygen sensor

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Fig. 2: The oxygen sensor can be locat ed on either the left, right or both
exhaust manifolds
REMOVAL & INSTALLATION
The sensor may be difficult to remove when the engine temperature is below
120°F (48°C). Excessive removal force may damage the threads in the exhaust
manifold or pipe; follow the removal procedure carefully.
1. Disconnect the negative battery cable.
2. Locate the oxygen sensor. It protr udes from the exhaust manifold (it
looks somewhat like a spark plug).
3. Disconnect the electrical wiring from the oxygen sensor harness.

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4. Spray a commercial solvent onto the sensor threads and allow it to soak
in for at least five minutes.
5. Carefully remove the sensor wit h a special oxygen sensor socket.
To install: 6. First coat the new sensor's th reads with GM anti-seize compound No.
5613695 or the equivalent. This is not a conventional anti-seize paste.
The use of a regular compound may el ectrically insulate the sensor,
rendering it inoperative. Y ou must coat the threads with an electrically
conductive anti-seize compound. Installati on torque is 30 ft. lbs. (41 Nm).
Do not overtighten.
7. Reconnect the electric al wiring. Be careful not to damage the electrical
pigtail. Check the sensor boot fo r proper fit and installation.
8. Reconnect the negative battery cable.
COOLANT TEMPERATURE SENSOR
OPERATION
Most engine functions are affected by the coolant temperature. Determining
whether the engine is hot or cold is largely dependent on the temperature of the
coolant. An accurate temperature signal to the ECM is supplied by the coolant
temperature sensor. The coolant temperatur e sensor is a thermistor mounted in
the engine coolant stream. A thermistor is an electrical device that varies its
resistance in relation to changes in temperature. Low coolant temperature
produces a high resistance and high coolant temperature produces low
resistance. The ECM supplies a signal of 5 volts to the coolant temperature
sensor through a resistor in the ECM and measures the voltage. The voltage
will be high when the engine is cold and low when the engine is hot.
REMOVAL & INSTALLATION
1. Disconnect the negative battery cable.
2. Drain the cooling system to an appropr iate and clean container for reuse.
3. Disconnect the electrical wiring fr om the coolant temperature sensor.
4. Remove the coolant temperature sensor.
To install: 5. Install the coolant temperature sensor.
6. Connect the electrical wiring.
7. Fill the cooling system.
8. Connect the negative battery cable.
9. Start the engine and check for leaks.