GM Service Manual Online
For 1990-2009 cars only
Table 1: IPC Indicators
Table 2: Message Center Indicators

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

IPC Indicators

Vehicle Indicator Name

Indicator Description Title

ABS symbol

ABS Indicator

4WD symbol

Driveline Indicators

Air Bag symbol (Canada)

Air Bag Indicator

AIR BAG (U.S.)

Air Bag Indicator

BRAKE symbol

Brake System Indicator

Check Engine symbol (Canada)

Malfunction Indicator Lamp (MIL)

CRUISE

Cruise Control Indicator

Engine Coolant Temperature Warning symbol

Engine Coolant Indicators

Fasten Safety Belt symbol

Fasten Safety Belt Indicator

Fog Lamp symbol

Lighting System Indicators

High Beam symbol

Lighting System Indicators

Lights On Reminder symbol (Canada)

Lighting System Indicators

LIGHTS ON (U.S.)

Lighting System Indicators

Oil Pressure symbol

Engine Oil Indicators

SERVICE ENGINE SOON (U.S.)

Malfunction Indicator Lamp (MIL)

UPSHIFT indicator

Transmission Indicators

TOW/HAUL

Transmission indicators

Turn Signal symbols

Lighting System Indicators

WAIT TO START (diesel)

Wait to Start Indicator

Message Center Indicators

Vehicle Indicator Name

Indicator Description Title

Battery symbol

Charging System Indicator

CARGO DOOR AJAR

Cargo Door Ajar Indicator

CARGO LAMP ON

Lighting System Indicators

CHANGE ENGINE OIL

Engine Oil Indicators

CHECK COOLANT TEMPERATURE

Engine Coolant Indicators

CHECK ENGINE OIL LEVEL

Engine Oil Indicators

CHECK ENGINE OIL PRESSURE

Engine Oil Indicators

ENGINE OVERHEATED

Engine Coolant Indicators

LOW COOLANT

Engine Coolant Indicators

LOW FUEL

Fuel System Indicators

LOW WASHER FLUID

Washer Fluid Indicator

OVER SPEED

Vehicle Over Speed Indicator

REDUCED ENGINE POWER

Engine Coolant Indicators

SECURITY

Theft System Indicator

SERVICE 4WD

Drive Line Indicators

SERVICE 4WHEEL STEER

Steering System Indicators

SERVICE RIDE CONTROL

Real Time Damping Indicator

SERVICE STABILITY SYSTEM

Stability System Indicators

SERVICE THROTTLE SOON (diesel)

Throttle System Indicators

STABILITY SYSTEM ACTIVE

Stability System Indicators

STABILITY SYSTEM DISABLED

Stability System Indicators

STABILITY SYSTEM LIMITED

Stability System Indicators

TRANS FLUID HOT

Transmission Indicators

TRANS HOT...IDLE ENG

Transmission Indicators

WATER IN FUEL (diesel)

Fuel System Indicators

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 EBCM performs the displays test at the beginning 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 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 requesting illumination. If the vehicle is shifted out of park with the park brake engaged, the BCM sends a class 2 message to the radio in order to activate an audible warning.
    • The IPC detects a low brake fluid condition (signal circuit is low).
    • The IPC performs the displays test at the start of each ignition cycle. The indicator illuminates for approximately 3 seconds.

Charging System Indicator

The IPC illuminates the charge indicator in the message center 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 determines that the system voltage is less than 11 volts or greater than 16 volts. The IPC receives a class 2 message from the body control module (BCM) indicating the system voltage.
    • 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.

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.

Driveline Indicators

4WD

The IPC illuminates the 4WD indicator when the PCM detects that the 4WD is requested. The IPC receives a class 2 message from the PCM requesting illumination. The IPC also performs the displays test at the start of each ignition cycle. The indicator illuminates for approximately 3 seconds.

SERVICE 4WD

The IPC illuminates the SERVICE 4WD indicator in the message center when the automatic transfer case module (ATC) detects a malfunction in the four wheel drive system. The IPC receives a class 2 message from the ATC requesting illumination.

Engine Coolant Indicators

CHECK COOLANT TEMP

The IPC illuminates the CHECK COOLANT TEMP indicator in the message center when the IPC determines that the coolant temperature is greater than 121°C (249.8°F). The IPC receives a class 2 message from the PCM indicating the coolant temperature.

ENGINE OVERHEATED

The IPC illuminates the ENGINE OVERHEATED indicator in the message center when the IPC determines that the coolant temperature is greater than 128°C (262°F). The IPC receives a class 2 message from the PCM indicating the coolant temperature.

LOW COOLANT

The IPC illuminates the LOW COOLANT indicator in the message center when the IPC detects a low coolant level condition from the PCM. The IPC receives a class 2 message from the PCM indicating the coolant level.

Engine Oil Indicators

CHANGE ENGINE OIL

The IPC illuminates the CHANGE ENGINE OIL indicator in the message center when the PCM determines that the engine oil should be changed. The IPC receives a class 2 message from the PCM requesting illumination. Once the oil is changed, perform the engine oil monitor reset procedure in order to clear the CHANGE ENGINE OIL indicator. Refer to GM Oil Life System Resetting in Maintenance and Lubrication.

CHECK ENG OIL LEVEL

The IPC illuminates the CHECK ENG OIL LEVEL indicator in the message center when the PCM detects a low engine oil level condition (signal circuit is high). An open engine oil level switch indicates a low engine oil level and a closed engine oil level switch indicates the engine oil level is in the normal range. The CHECK ENG OIL LEVEL indicator illuminates for 60 seconds at the start of each ignition cycle when a low engine oil level condition is present. The IPC receives a class 2 message from the PCM requesting illumination. The IPC sends a class 2 message to the radio in order to activate an audible warning.

CHECK ENGINE OIL PRESSURE

The IPC illuminates the CHECK ENG OIL PRESSURE indicator in the message center when the IPC detects low oil pressure from the engine oil pressure sensor signal. The CHECK ENG OIL PRESSURE indicator will illuminate in the message center when this condition is present.

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. 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 also sends a class 2 message to the BCM in order to activate the 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 SDM.

Fuel System Indicators

LOW FUEL

The IPC illuminates the LOW FUEL indicator in the message center when the IPC detects 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 percent. The IPC sends a class 2 message to the radio in order to activate an audible warning.

WATER IN FUEL (DIESEL ONLY)

The IPC Illuminates the WATER IN FUEL indicator in the message center as determined by the PCM. The IPC receives a class 2 message from the PCM requesting illumination when it detects water in the diesel fuel.

Hatch/Gate Ajar Indicator

The IPC illuminates the CARGO DOOR AJAR indicator in the message center when the body control module (BCM) detects that the cargo door is open. The IPC receives a class 2 message from the BCM requesting illumination.

Lighting System Indicators

CARGO LAMP ON

The IPC illuminates the CARGO LAMP ON indicator in the message center when the body control module (BCM) detects that the cargo lamp is on. The IPC receives a class 2 message from the BCM requesting illumination.

Fog Lamp

The IPC illuminates the fog lamp indicator when the body control module (BCM) detects that the fog lamps are requested. The IPC receives a class 2 message from the BCM requesting illumination.

HEADLAMPS SUGGESTED

The IPC illuminates the HEADLAMPS SUGGESTED indicator in the message center when the following occurs:

    • The Twilight Sentinel control is turned off.
    • The ambient light sensor detects it is dark enough outside that the headlamps and/or other exterior lamps are recommended.

High Beam

The IPC illuminates the high beam indicator when the body control module (BCM) detects that the high beams are requested. The IPC receives a class 2 message from the BCM requesting illumination.

HIGHBEAM OUT

The IPC illuminates the HIGHBEAM OUT indicator in the message center when the body control module (BCM) detects an open in one of the highbeam lamp circuits. The IPC receives a class 2 message from the BCM requesting illumination.

LIGHTS ON

The IPC illuminates the LIGHTS ON indicator when the dash integration module (DIM) detects that the park lamps are requested. The IPC receives a class 2 message from the DIM indicating the park lamps status. The IPC continues to illuminate the indicator for 10 minutes when the ignition is turned OFF and the park lamps are active. After 10 minutes, the IPC requests the status of the lighting system from the DIM and continues to illuminate the indicator only if the park lamps status is active.

Turn Signals

The IPC illuminates the right or left turn signal indicator when the IPC detects a turn signal request or a hazard request. If the body control module (BCM) determines that the turn signal is active for more than 1.20 km (0.75 mi), it activates an audible warning to alert the driver.

TURN SIGNAL ON?

The IPC illuminates the TURN SIGNAL ON? indicator in the message center when the IPC determines that the turn signal is active for more than 1.20 km (0.75 mi). The body control module (BCM) will also 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.

Real Time Damping Indicator

The IPC illuminates the SERVICE RIDE CONTROL indicator in the message center when the Real Time Damping (RTD) module detects a malfunction in the autoride system. The IPC receives a class 2 message from RTD module requesting illumination.

Reduced Engine Power Indicator

The IPC illuminates the reduced engine power indicator in the message center when the PCM detects a malfunction in the throttle actuator control (TAC) system. The IPC receives a class 2 message from the PCM requesting illumination.

Stability System Indicators

SERVICE STABILITY SYSTEM

The IPC illuminates the SERVICE STABILITY SYSTEM indicator in the message center when the VSES module detects a malfunction in the stability system. The IPC receives a class 2 message from the VSES module requesting illumination.

STABILITY SYSTEM ACTIVE

The IPC illuminates the STABILITY ACTIVE indicator in the message center when the VSES module detects the stability system is active. The IPC receives a class 2 message from the VSES module requesting illumination.

STABILITY SYSTEM LIMITED

The IPC illuminates the STABILITY LIMITED indicator in the message center when the VSES module detects a limited stability system. The IPC receives a class 2 message from the VSES module requesting illumination.

STABILITY SYSTEM DISABLED

The IPC illuminates the STABILITY DISABLED indicator in the message center when the VSES module detects the stability system is disabled. The IPC receives a class 2 message from the VSES module requesting illumination.

Steering System Indicator

SERVICE 4WHEEL STEER

The IPC illuminates the SERVICE 4WHEEL STEER indicator in the message center when the QS4 module detects a malfunction in the 4WHEEL STEER system. The IPC receives a class 2 message from the QS4 module requesting illumination.

Theft System Indicators

The IPC illuminates the SECURITY indicator in the message center as determined by the vehicle theft deterrent (VTD) system and the content theft deterrent (CTD) system. The IPC receives a class 2 message from the BCM 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 CTD system requests the IPC to illuminate the indicator only when the ignition switch is OFF. The CTD system uses the indicator in order to identify system status.
    • ON
    • OFF
    • Flashing slow
    • Flashing fast

If the SECURITY indicator flashes or stays ON continuously during the vehicle operation, refer to the system diagnosis.

Throttle System Indicator

The IPC illuminates the SERVICE THROTTLE SOON indicator in the message center when the PCM detects a malfunction with the throttle system. The IPC receives a class 2 message from the PCM requesting illumination.

Transmission Indicators

The IPC receives a class 2 message from the PCM indicating the transmission fluid temperature.

SHIFT (MANUAL TRANSMISSION ONLY)

The IPC illuminates the SHIFT indicator as determined by the powertrain control module (PCM). The IPC receives a class 2 message from the PCM requesting illumination.

TOW/HAUL (AUTOMATIC TRANSMISSION ONLY)

The IPC illuminates the TOW/HAUL indicator when the body control module (BCM) detects that the tow/haul is requested. The IPC receives a class 2 message from the BCM requesting illumination.

TRANS FLUID HOT

The IPC illuminates the TRANS FLUID HOT indicator in the message center when the IPC determines that the transmission fluid temperature is greater than or equal to 130°C (266°F).

TRANS HOT...IDLE ENG

The IPC illuminates the TRANS HOT...IDLE ENG indicator in the message center when the IPC determines that the transmission fluid temperature is greater than or equal to 135°C (275°F).

Vehicle Over Speed Indicator (Kilometer Only)

The IPC illuminates the OVER SPEED indicator in the message center when the BCM detects the vehicle speed is above 120 km/h (75 mph). The IPC receives a class 2 message from the BCM requesting illumination of the over speed indicator.

Wait To Start Indicator (Diesel Only)

The IPC illuminates the WAIT TO START indicator via a hard-wired circuit to the PCM. The indicator illuminates in the IPC when the ignition is on and the engine is off. The indicator is pulled high to the ignition 1 fuse block in the IPC. The PCM illuminates the indicator by providing a low signal (grounding) to the WAIT TO START indicator control circuit.

Washer Fluid Indicator

The IPC illuminates the LOW WASHER FLUID indicator in the message center when the IPC detects a low washer fluid condition (signal circuit is low). The LOW WASHER FLUID indicator illuminates for 60 seconds when the condition is present.