ABS Inop Indicator
The ABS Inop indicator is controlled by either of the following components:
• | The electronic brake control module (EBCM) |
The EBCM sends a Class 2 message through circuit 1036 to the instrument
cluster to turn on the ABS inop indicator when a problem with the ABS system
has been detected. The ABS system may be disabled, but base brake performance
will remain.
The instrument cluster turns on the ABS Inop indicator under the following
conditions:
• | Class 2 communication has been lost between the instrument cluster
and the EBCM. |
• | The 3 second bulb test is occurring. |
Air Bag Indicator
The air bag indicator is controlled by either of the following components:
• | The inflatable restraint sensing and diagnostic module (SDM) |
The SDM sends a Class 2 message through circuit 1036 to the instrument
cluster to turn on the indicator when a problem with the SIR system has been
detected.
The instrument cluster turns on the air bag indicator under the following
conditions:
• | Class 2 communication has been lost between the instrument cluster
and the SDM. |
• | The 3 second bulb test is occurring. |
If the instrument cluster detects a fault in the air bag indicator,
the cluster sets DTC B0670 and illuminates the Service Vehicle Soon indicator.
ASR Off Indicator (Chevrolet with Traction Control Only)
The ASR off indicator is controlled by either of the following components:
• | The electronic brake control module (EBCM) |
The EBCM sends a Class 2 message through circuit 1036 to the instrument
cluster to turn on the ASR off indicator. The EBCM turns on the indicator
under any of the following conditions:
• | The traction control system is off. |
• | The traction control system has failed. |
• | Class 2 communication has been lost between the instrument cluster
and the EBCM. |
• | The 3 second bulb test is occurring. |
Brake Warning Indicator
The brake warning indicator lights under any of the following conditions:
• | The master cylinder senses a low brake fluid level. |
• | The park brake switch is closed (park brake is set). |
• | The EBCM senses a base brake failure. |
• | Class 2 communication has been lost between the instrument cluster
and the EBCM. |
• | The 3 second bulb test is occurring. |
Change Oil Indicator
The change oil indicator is controlled by either of the following components:
• | The powertrain control module (PCM) |
The PCM sends a Class 2 message through circuit 1036 to the instrument
cluster to turn on the change oil indicator when the engine oil is due to
be changed. After the Class 2 message is sent from the PCM, the instrument
cluster turns on the change oil indicator for approximately 60 seconds
when the ignition switch is turned to the RUN position. The indicator is
turned on every following ignition cycle until it is reset.
Perform the following steps in order to reset the change oil indicator:
- Turn the ignition switch to the RUN position with the engine off.
- Press and hold the trip odometer reset button for approximately
12 seconds.
When the change oil reset is completed, the PCM will flash the indicator
twice through the Class 2 data line (circuit 1036).
Under normal conditions, the instrument cluster turns on the change
oil indicator for approximately 3 seconds at bulb test.
Check Gauges Indicator
The check gauges indicator turns on in order to draw the driver's attention
to the instrument cluster gauges. The check gauges indicator turns on under
any of the following conditions:
• | The engine coolant temperature exceeds 107.2°C (225°F). |
• | The engine oil pressure is low. |
• | The generator malfunctions. |
• | The vehicle fuel level falls below approximately 1/16 tank. |
The powertrain control module (PCM) sends a Class 2 message to turn
on the check gauges indicator depending on the signals it receives from the
following components:
• | The engine coolant temperature sensor |
The instrument cluster turns on the check gauges indicator for approximately
3 seconds at bulb test.
Engine Coolant Temperature Gauge
The engine coolant temperature gauge is controlled by the powertrain
control module (PCM). The PCM monitors the engine coolant temperature sensor
and sends the Class 2 information to the instrument cluster through circuit
1036. The temperature gauge displays the coolant temperature based on the
Class 2 information it receives from the PCM.
Fasten Belts Indicator
The fasten seat belt indicator is controlled by the body control module
(BCM). The BCM monitors the driver seat belt switch. If the driver seat belt
is not buckled, the BCM applies voltage to the instrument cluster through
circuit 237 at terminal A13 in order to illuminate the indicator. The indicator
remains illuminated for approximately 70 seconds. The indicator turns
off immediately if the seatbelt is buckled.
If the driver seat belt is buckled when the ignition switch is turned
to the RUN or START position, the fasten seat belt indicator does not illuminate.
Fuel Gauge
The fuel gauge is controlled by the powertrain control module (PCM).
The PCM monitors the fuel level sensor and sends the Class 2 information to
the instrument cluster through circuit 1036. The fuel gauge displays the
fuel level based on the Class 2 information sent from the PCM.
When the fuel level sensor reads the fuel level at less than 1/16 full,
the PCM sends a Class 2 message to the instrument cluster through circuit
1036 in order to turn on the check gauges indicator.
Hatch Ajar Indicator
The hatch ajar indicator receives battery voltage when the ignition
switch is in the following positions:
The hatch ajar indicator is controlled by the rear compartment lid ajar
indicator switch. The rear compartment lid ajar indicator switch closes when
the rear compartment lid is open or ajar. The indicator turns on when the
switch closes and ground is applied to the hatch ajar indicator through
circuit 737.
High Beam Indicator
The high beam indicator is controlled by the headlamp dimmer switch.
The high beam indicator turns on under the following conditions:
• | The headlamp dimmer switch is in the high beam position. |
Voltage is applied to the instrument cluster at terminal A17 through
circuit 11 to turn on the indicator.
Low Oil Indicator
The low oil indicator is controlled by either of the following components:
• | The powertrain control module (PCM) |
The PCM receives oil level information from the engine oil level switch.
When a low engine oil condition exists, the PCM sends a Class 2 message through
circuit 1036 to the instrument cluster in order to turn on the low oil indicator.
The instrument cluster turns the low oil indicator on for approximately
3 seconds at bulb test.
Trac Indicator
The trac indicator is controlled by either of the following components:
• | The electronic brake control module (EBCM) |
The EBCM sends a Class 2 message through circuit 1036 to the instrument
cluster in order to turn on the trac indicator. The EBCM turns on the indicator
under one of the following conditions:
• | The anti-lock brake system is active. |
• | The traction control system is active. |
• | The 3 second bulb test is occurring. |
Oil Pressure Gauge
The oil pressure gauge receives battery voltage through circuit 1035
when the ignition switch is in the following positions:
The oil pressure gauge is controlled by the engine oil pressure sensor.
The resistance of the engine oil pressure sensor varies with the engine oil
pressure. The voltage drop across the oil pressure gauge varies due to the
changing resistance in the gauge ground circuit. The oil pressure gauge
reading changes with the voltage drop.
Reduced Engine Power Indicator (V6 VIN K Only)
The reduced engine power indicator is controlled by the following components:
• | The powertrain control module (PCM) |
The PCM sends a Class 2 message through circuit 1036 to the instrument
cluster in order to turn on the indicator when problems with the engine have
been detected.
The instrument cluster turns on the reduced engine power indicator under
the following conditions:
• | Class 2 communication has been lost between the instrument cluster
and the PCM. |
• | The 3 second bulb test is occurring. |
Security Indicator
The security indicator is controlled by the body control module (BCM).
The BCM monitors the ignition key resistor pellet. If the resistor pellet
is incorrect, the BCM applies ground to the instrument cluster through circuit
728 at terminal B3 in order to illuminate the indicator. For a complete understanding
of the security indicator operation, refer to the
Vehicle Theft Deterrent (VTD) Operation
.
The BCM turns on the security indicator for approximately 5 seconds
at bulb test.
Skip Shift Indicator (V8 VIN G Manual Transmission Only)
The skip shift indicator is controlled by the following components:
• | The powertrain control module (PCM) |
The PCM sends a Class 2 message through circuit 1036 to the instrument
cluster in order to turn on the indicator when the transmission skip shift
function is enabled.
The instrument cluster turns on the skip shift indicator for approximately
3 seconds at bulb test.
Service Engine Soon Indicator
The powertrain control module (PCM) controls the service engine soon
indicator.
Service Vehicle Indicator
The service vehicle indicator is controlled by the following components:
• | The powertrain control module (PCM) |
The PCM sends a Class 2 message through circuit 1036 to the instrument
cluster in order to turn on the indicator when problems with the engine have
been detected.
The instrument cluster turns on the service soon indicator under the
following conditions:
• | Class 2 communication has been lost between the instrument cluster
and any other module (PCM, SDM, EBCM). |
• | The air bag indicator is defective. DTC B0670 is set. |
• | The 3 second bulb test is occurring. |
Speedometer and Odometer
The vehicle speed sensor (VSS) is a gear driven permanent magnet generator
housed in the transaxle. The sensor generates a sine wave output with a frequency
proportional to the vehicle speed. The powertrain control module (PCM) converts
the signal to an output that switches to ground at a frequency of 4000 pulses
per mile. The signal (circuit 389) drives the speedometer and the
odometer.
Tachometer
The tachometer is controlled by the powertrain control module (PCM).
The PCM monitors the engine RPMs and sends the Class 2 information to the
instrument cluster through circuit 1036. The tachometer displays the engine
RPMs based on the Class 2 information sent from the PCM.
TCS Off Indicator (Pontiac with traction control only)
The TCS off indicator is controlled by either of the following components:
• | The electronic brake control module (EBCM) |
The EBCM sends a Class 2 message through circuit 1036 to the instrument
cluster to turn on the TCS off indicator. The EBCM turns on the indicator
under any of the following conditions:
• | The traction control system is off. |
• | The traction control system has failed. |
• | Class 2 communication has been lost between the instrument cluster
and the EBCM. |
• | The 3 second bulb test is occurring. |
The instrument cluster turns the TCS indicator on for approximately
3 seconds at bulb test.
Turn Signal Indicators
The turn signal switch is used to control the turn signal lamps. Voltage
is sent to the instrument cluster in order to turn on the turn signal indicators.
If the emergency flashers are turned on, both of the turn signal indicators
will flash.