GM Service Manual Online
For 1990-2009 cars only

The indicator description and operation uses generic indicator names. Refer to the IPC Indicators table for the indicators that are available on this vehicle:

IPC Indicators

Vehicle Indicator Name

Indicator Description Title

ABS symbol

ABS Indicator

ANTI-LOCK

ABS Indicator

Air Bag symbol

Air Bag Indicator

AIR BAG

Air Bag Indicator

Brake symbol

Brake System Indicator

BRAKE

Brake System Indicator

CHANGE OIL

Engine Oil Indicator(s)

Charging System symbol

Charging System Indicator

Check Engine symbol

Malfunction Indicator Lamp (MIL)

CRUISE

Cruise Control Indicator

Engine Coolant Temperature symbol

Engine Coolant Indicator(s)

Engine Oil Pressure symbol

Engine Oil Indicator(s)

Fasten Safety Belt symbol

Fasten Safety Belt Indicator

High Beam symbol

Lighting System Indicator(s)

LOW COOLANT

Engine Coolant Indicator(s)

Low Engine Coolant symbol

Engine Coolant Indicator(s)

Low Fuel symbol

Fuel System Indicator

LOW OIL

Engine Oil Indicator(s)

LOW TIRE PRESSURE

Tire Pressure Indicator(s)

LOW TRAC

Traction Control System Indicator(s)

Low Washer Fluid symbol

Washer Fluid Indicator

LOW WASHER FLUID

Washer Fluid Indicator

SECURITY

Theft System Indicator

SERVICE ENGINE SOON

Malfunction Indicator Lamp (MIL)

SERVICE VEHICLE SOON

Electrical System Indicator

SHIFT

Shift Indicator

TRAC OFF

Traction Control Indicator(s)

Turn Signal Symbol

Lighting System Indicator(s)

ABS Indicator

The IPC illuminates the ABS indicator when the following occurs:

    • The electronic brake control module (EBCM) detects a malfunction with the antilock brake system. The IPC receives a class 2 message from the EBCM requesting illumination. The IPC sends a class 2 message to the body control module (BCM) indicating that the ABS indicator is illuminated. The BCM sends a class 2 message to the radio in order to activate an audible warning.
    • The IPC performs the displays test at the start of each ignition cycle. The indicator illuminates for approximately 3 seconds.
    • The IPC detects a loss of class 2 communications with the EBCM.

Air Bag Indicator

The IPC illuminates the air bag indicator when the following occurs:

    • The inflatable restraint sensing and diagnostic module (SDM) detects a malfunction with the supplemental inflatable restraint system. The IPC receives a class 2 message from the SDM requesting illumination. The IPC sends a class 2 message to the body control module (BCM) indicating that the air bag indicator is illuminated. The BCM sends a class 2 message to the radio in order to activate an audible warning.
    • The IPC performs the displays test at the start of each ignition cycle. The IPC flashes the air bag indicator 7 times.
    • The IPC detects a loss of class 2 communications with the SDM.

Brake System Indicator

The IPC illuminates the brake indicator when the following occurs:

    • The body control module (BCM) detects that the park brake is engaged. The IPC receives a class 2 message from the BCM indicating the park brake status. If the vehicle speed is greater than 5 km/h (3.1 mph) with the park brake engaged, the BCM sends a class 2 message to the radio in order to activate an audible warning.
    • The electronic brake control module (EBCM) detects a low brake fluid condition (signal circuit is low). The IPC receives a class 2 message from the EBCM requesting illumination. The IPC sends a class 2 message to the BCM indicating that the brake indicator is illuminated due to a brake malfunction. The BCM sends a class 2 message to the radio in order to activate an audible warning.
    • The EBCM detects a malfunction in the braking system. The IPC receives a class 2 message from the EBCM requesting illumination. The IPC sends a class 2 message to the BCM indicating that the brake indicator is illuminated due to a brake malfunction. The BCM sends a class 2 message to the radio in order to activate an audible warning.
    • The IPC performs the displays test at the start of each ignition cycle. The indicator illuminates for approximately 3 seconds.
    • The IPC detects a loss of class 2 communications with the EBCM.

Charging System Indicator

The IPC illuminates the charging system indicator when the following occurs:

    • The PCM detects that the generator output is less than 11 volts or greater than 16 volts. The IPC receives a class 2 message from the PCM requesting illumination. The IPC sends a class 2 message to the body control module (BCM) indicating that the charging system indicator is illuminated. The BCM sends a class 2 message to the radio in order to activate an audible warning.
    • The IPC performs the displays test at the start of each ignition cycle. The indicator illuminates for approximately 3 seconds.
    • The ignition is on, with the engine off.
    • The ignition is in the accessory position.

Cruise Control Indicator

The IPC illuminates the CRUISE indicator when the PCM detects that the cruise control is requested. The IPC receives a class 2 message from the PCM requesting illumination.

Electrical System Indicator

SERVICE VEHICLE SOON

The IPC illuminates the SERVICE VEHICLE SOON indicator when the following occurs:

    • The body control module (BCM) detects certain malfunctions in the lighting system. The IPC receives a class 2 message from the BCM requesting illumination. The IPC sends a class 2 message to the BCM indicating that the service vehicle soon indicator is illuminated. The BCM sends a class 2 message to the radio in order to activate an audible warning.
    • The electronic brake control module (EBCM) detects a malfunction in the traction control system. The IPC receives class 2 messages from the EBCM requesting illumination of both the service vehicle soon and traction off indicators.
    • The IPC performs the displays test at the start of each ignition cycle. The indicator illuminates for approximately 3 seconds.
    • The IPC detects a loss of class 2 communications with the BCM.

Engine Coolant Indicator(s)

Engine Coolant Temperature

The IPC illuminates the engine coolant temperature indicator when the IPC determines that the coolant temperature is greater than 123°C (253°F). The IPC receives a class 2 message from the PCM indicating the coolant temperature. The IPC sends a class 2 message to the body control module (BCM) indicating that the engine coolant temperature indicator is illuminated. The BCM sends a class 2 message to the radio in order to activate an audible warning.

Low Engine Coolant

The IPC illuminates the low engine coolant indicator when the following occurs:

    • The body control module (BCM) detects a low coolant level condition (signal circuit is low) for greater than 10 seconds and the ignition is ON. The IPC receives a class 2 message from the BCM requesting illumination. The IPC sends a class 2 message to the BCM indicating that the low engine coolant indicator is illuminated. The BCM sends a class 2 message to the radio in order to activate an audible warning.
    • The IPC performs the displays test at the start of each ignition cycle. The indicator illuminates for approximately 3 seconds.

Engine Oil Indicator(s)

CHANGE OIL

The IPC illuminates the CHANGE OIL indicator when the following occurs:

    • The PCM determines that the engine oil should be changed. The IPC receives a class 2 message from the PCM indicating the remaining oil life percent. The IPC illuminates the CHANGE OIL indicator when the remaining oil life is less than 11 percent. The IPC sends a class 2 message to the body control module (BCM) indicating that the CHANGE OIL indicator is illuminated. The BCM sends a class 2 message to the radio in order to activate an audible warning.
    • The IPC performs the displays test at the start of each ignition cycle. The indicator illuminates for approximately 3 seconds.

Once the oil is changed, perform the engine oil monitor reset procedure in order to clear the CHANGE OIL indicator. Refer to GM Oil Life System Resetting in Maintenance and Lubrication. The BCM monitors the oil life/TPM reset switch signal circuit and sends a class 2 message to the IPC indicating that the oil life/TPM reset switch is active (signal circuit is low). The IPC turns off the indicator when the IPC determines that a request to reset the oil life has been activated via the oil life/TPM reset switch. The IPC sends a class 2 message to the PCM in order to reset the oil life to 100 percent.

Engine Oil Pressure

The IPC illuminates the engine oil pressure indicator when the following occurs:

    • The PCM detects low oil pressure (signal circuit is low). The IPC receives a class 2 message from the PCM requesting illumination. The IPC sends a class 2 message to the body control module (BCM) indicating that the engine oil pressure indicator is illuminated. The BCM sends a class 2 message to the radio in order to activate an audible warning.
    • The IPC performs the displays test at the start of each ignition cycle. The indicator illuminates for approximately 3 seconds.

LOW OIL

The IPC illuminates the LOW OIL indicator when the following occurs:

    • The PCM detects a low engine oil level condition (signal circuit is high). The PCM only monitors the oil level switch signal circuit for a brief period between key on and engine crank. The IPC receives a class 2 message from the PCM requesting illumination. The IPC sends a class 2 message to the body control module (BCM) indicating that the LOW OIL indicator is illuminated. The BCM sends a class 2 message to the radio in order to activate an audible warning.
    • The IPC performs the displays test at the start of each ignition cycle. The indicator illuminates for approximately 3 seconds.

Fasten Safety Belt Indicator

The IPC illuminates the fasten safety belt indicator when the following occurs:

    • The body control module (BCM) detects that the driver's seat belt is unbuckled (signal circuit is low). The IPC receives a class 2 message from the BCM requesting illumination. The IPC illuminates the indicator for 20 seconds and then flashes the indicator for 55 seconds. The IPC sends a class 2 message to the BCM indicating the indicator is illuminated. The BCM sends a class 2 message to the radio in order to activate an audible warning.
    • The IPC performs the displays test at the start of each ignition cycle. The indicator illuminates for approximately 3 seconds.
    • The IPC detects a loss of class 2 communications with the BCM.

Fuel System Indicator

Low Fuel

The IPC illuminates the low fuel indicator when the following occurs:

    • The IPC determines that the fuel level is less than a pre-determined value. The IPC receives a class 2 message from the PCM indicating the fuel level volume. The IPC sends a class 2 message to the body control module (BCM) indicating that the low fuel indicator is illuminated. The BCM sends a class 2 message to the radio in order to activate an audible warning.
    • The PCM detects a malfunction in the fuel level sensor circuit. The IPC sends a class 2 message to the BCM indicating that the low fuel indicator is illuminated. The BCM sends a class 2 message to the radio in order to activate an audible warning.
    • The IPC detects a loss of class 2 communications with the PCM.

Lighting System Indicator(s)

High Beam

The IPC illuminates the high beam indicator when the body control module (BCM) detects that the high beams are requested. The BCM divides the voltage present on the headlamp high beam signal circuit by the system voltage in order to determine a percentage value. This value is compared against a calibration in order to determine if the high beams are on. The BCM sends a class 2 message to the IPC requesting illumination.

Turn Signals

The right and left turn signal indicators are hard wired to the turn signal switch and the hazard switch. The turn signal indicator illuminates when the turn signal lamps supply voltage circuit is active. The BCM is also hard wired to the turn signal switch. If the BCM determines that the turn signal flasher signal circuit is active for more than 1.2 km (0.75 mi), the BCM sends a class 2 message to the radio in order to activate an audible warning.

Malfunction Indicator Lamp (MIL)

The PCM illuminates the MIL (service engine soon or check engine) when the following occurs:

    • The PCM detects a malfunction in the emissions system.
    • The PCM performs the displays test at the start of each ignition cycle. The indicator illuminates for approximately 3 seconds.
    • The ignition is on, with the engine off.

Shift Indicator

The IPC illuminates the shift indicator when the following occurs:

    • The PCM determines that the vehicle should be shifted to the next higher gear. The IPC receives a class 2 message from the PCM requesting illumination.
    • The IPC performs the displays test at the start of each ignition cycle. The indicator illuminates for approximately 3 seconds.

Theft System Indicator

The IPC illuminates the theft system indicator as determined by the vehicle theft deterrent (VTD) system. The body control module (BCM) sends a class 2 message to the IPC requesting illumination.

    • The VTD system requests the IPC to illuminate the indicator only when the ignition switch is ON. The VTD system uses the indicator as a malfunction indicator.
    • The IPC performs the displays test at the start of each ignition cycle. The indicator illuminates for approximately 3 seconds.

Tire Pressure Indicator

The IPC illuminates the LOW TIRE PRESSURE indicator when the following occurs:

    • The electronic brake control module (EBCM) detects low pressure in any of the 4 tires. The IPC receives a class 2 message from the EBCM requesting illumination. The IPC sends a class 2 message to the body control module (BCM) indicating that the LOW TIRE PRESSURE indicator is illuminated. The BCM sends a class 2 message to the radio in order to activate an audible warning.
    • The IPC performs the displays test at the start of each ignition cycle. The indicator illuminates for approximately 3 seconds.

Once the tire pressures are properly adjusted, perform the tire pressure monitor reset procedure in order to clear the LOW TIRE PRESSURE indicator. Refer to Tire Pressure Monitor Procedure in Tire Pressure Monitoring. The BCM monitors the oil life/TPM reset switch signal circuit and sends a class 2 message to the IPC indicating that the oil life/TPM reset switch is active (signal circuit is low). The IPC turns off the indicator when the IPC determines that a request to reset the tire pressure monitoring system has been activated via the oil life/TPM reset switch. The IPC sends a class 2 message to the EBCM indicating that the reset procedure has been performed.

Traction Control System Indicator(s)

Low Traction

The IPC illuminates the low traction indicator when the following occurs:

    • The electronic brake control module (EBCM) detects a traction control event. The IPC receives a class 2 message from the EBCM requesting illumination.
    • The IPC performs the displays test at the start of each ignition cycle. The indicator illuminates for approximately 3 seconds.

Traction Off

The IPC illuminates the traction off indicator when the following occurs:

    • The electronic brake control module (EBCM) inhibits the traction control system. The IPC receives a class 2 message from the EBCM requesting illumination. The traction control system is disabled when the following occurs:
       - For Chevrolet only, the shift lever is in FIRST (1) or SECOND (2) gear. The EBCM receives a class 2 message from the powertrain control module (PCM) indicating the gear position.
       - For Pontiac and Oldsmobile only, the body control module (BCM) detects that the traction control switch is pressed (signal circuit is low). The EBCM receives a class 2 message from the BCM indicating the switch status.
       - The BCM detects that the park brake is engaged (signal circuit is low) and that the engine is on. The EBCM receives a class 2 message from the BCM indicating the park brake status.
       - The PCM detects certain malfunctions and is unable to perform torque reduction requests from the EBCM. The EBCM receives a class 2 message from the PCM indicating that traction control cannot be performed.
    • The EBCM detects a malfunction in the traction control system. The IPC receives class 2 messages from the EBCM requesting illumination of both the service vehicle soon and traction off indicators.
    • The IPC performs the displays test at the start of each ignition cycle. The indicator illuminates for approximately 3 seconds.

Washer Fluid Indicator

The IPC illuminates the low washer fluid indicator when the following occurs:

    • The body control module (BCM) detects a low washer fluid condition (signal circuit is low) for greater than 30 seconds. The IPC receives a class 2 message from the BCM requesting illumination. The IPC sends a class 2 message to the BCM indicating that the low washer fluid indicator is illuminated. The BCM sends a class 2 message to the radio in order to activate an audible warning.
    • The IPC performs the displays test at the start of each ignition cycle. The indicator illuminates for approximately 3 seconds.