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

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

IPC Indicators

Vehicle Indicator Name

Indicator Description Title

Battery symbol

Charging System Indicators

CHECK GAUGES

Check Gauges Indicator

High Beam symbol

Lighting System Indicators

Turn Signal symbols

Lighting System Indicators

DIC Indicators

Vehicle Indicator Name

Indicator Description Title

ABS

ABS Indicator

AUX BRAKE

Hydraulic Brake Indicators

CHANGE ENGINE OIL

Engine Oil Indicators

DRL

Lighting System Indicators

ENGINE OVERSPEED

Engine Overspeed Indicators

ENGINE POWER REDUCED

Reduced Engine Power Indicator

FAST IDLE

Idle Control Indicator

INTAKE HEATER

Intake Heater Indicators

LOW AIR

Air Brake Indicator

LOW COOLANT

Intake Heater Indicator

PARK BRAKE

Park Brake Indicator

SERVICE ENGINE SOON

Malfunction Indicator Lamp (MIL)

SERVICE TRANS FILTER

Transmission Indicator

WAIT TO START

Wait To Start Indicator

WATER IN FUEL

Fuel System Indicator

ABS Indicator

The ABS indicator illuminates in the DIC when the following occurs:

    • The electronic brake control module (EBCM) detects a malfunction in the ABS system.
    • The displays test is performed in the DIC at the start of each ignition cycle. The indicator illuminates for approximately 3 seconds.

Air Brake Indicator

The LOW AIR indicator illuminates in the DIC when the following occurs:

    • The air pressure drops below 65 psi (448 kPa) (switch signal is low). The multifunction alarm module (MFAM) monitors the low air pressure switch and activates an alarm when it detects the air pressure is low.
    • The multifunction alarm module (MFAM) performs the displays test at the beginning of each ignition cycle.

Charging System Indicator

The charge indicator illuminates in the IPC when the following occurs:

    • The generator output is less than 11 volts or more than 16 volts.
    • The displays test is performed in the IPC at the start of each ignition cycle. The indicator illuminates for approximately 3 seconds.
    • The ignition is ON, with the engine OFF.

Check Gauges Indicator

The CHECK GAUGES indicator illuminates in the IPC when the following occurs:

    • The multifunction alarm module (MFAM) detects that the engine oil pressure is approximately 5 psi (34 kPa) or below.
    • The MFAM detects that the engine coolant temperature is approximately 118°C (245°F) or above.
    • The MFAM detects the engine coolant level is below the coolant level probe.
    • The engine is about to be shutdown (if equipped with automatic engine shutdown). When an extreme high coolant temperature or a low engine oil pressure condition is present, the MFAM will activate the CHECK GAUGES indicator and an audible warning. After approximately 25 seconds the MFAM will send a signal to the PCM to stop fuel flow at the injectors and shutdown the engine.
    • The displays test is performed by the MFAM at the beginning of each ignition cycle.

In any of these conditions the MFAM activates an audible warning.

Engine Coolant Indicator

LOW COOLANT

The multifunction alarm module illuminates the LOW COOLANT indicator in the DIC when it detects a low coolant level from the coolant level switch signal circuit (signal is low). The multifunction alarm module also activates an audible warning for about 10 seconds.

Engine Oil Indicator

CHANGE OIL

The CHANGE OIL indicator illuminates in the DIC when the PCM detects that the engine oil should be changed. The PCM is hard-wired to the CHANGE OIL indicator and activates the indicator by grounding the indicator lamp. 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.

Engine Overspeed Indicator

The ENGINE OVERSPEED indicator illuminates in the DIC when the PCM detects the engine speed is between 3,600 and 4,000 rpm. The PCM grounds the engine overspeed indicator control circuit.

Fuel System Indicator

WATER IN FUEL (DIESEL ENGINE ONLY)

The WATER IN FUEL indicator illuminates in the DIC when the following occurs:

    • The water in fuel sensor (primary or secondary sensor) detects water in the fuel tank (signal is low).
    • The displays test is performed at the beginning of each ignition cycle. The indicator illuminates for approximately 3 seconds.

Hydraulic Brake Indicators

AUX BRAKE

The multifunction alarm module (MFAM) illuminates the AUX BRAKE indicator in the DIC when the following occurs:

    • The MFAM detects a malfunction in the auxiliary brake system. The MFAM provides power to the indicator control circuit and will activate an audible warning.
    • The MFAM performs the displays test at the beginning of each ignition cycle. The indicator illuminates for approximately 3 seconds.

PRIMARY BRAKE

The PRIMARY BRAKE indicator illuminates in the DIC when the following occurs:

    • The hydraulic brake fluid condition is low (switch signal is low). The multifunction alarm module (MFAM) activates an audible warning indicating a low fluid level.
    • The MFAM performs the displays test at the beginning of each ignition cycle. The indicator illuminates for approximately 3 seconds.

Idle Control Indicator

FAST IDLE

The FAST IDLE indicator illuminates in the DIC when the following occurs:

    • The PCM detects fast idle is requested from the switch or the fast idle system automatically engages under a certain preset temperature condition. The PCM grounds the fast idle indicator control circuit.
    • The vehicle is started and the park brake is applied.

Intake Heater Indicator

The engine control module (ECM) illuminates the intake heater indicator lamp in the DIC via the intake heater relay (signal is low). The relay activates the indicator via the intake heater indicator control circuit by providing battery positive voltage to the indicator.

Lighting System Indicators

DAYTIME RUNNING LAMPS (DRL)

The DRL relay illuminates the DRL indicator in the DIC when the following occurs:

    • The DRL's are activated. The DRL indicator relay grounds the DRL indicator control circuit.
    • The ambient light conditions are low. The DRL indicator relay grounds the DRL indicator control circuit.

HIGH BEAM

The HIGH BEAM indicator illuminates in the IPC when the high beams are requested from the headlamps dimmer switch.

TURN SIGNALS

The turn signal indicators illuminate in the IPC when the ignition is ON and the left or right turn signal is requested from the switch. An audible warning is also activated by the multifunction alarm module as a reminder that the turn signal is ON .

Malfunction Indicator Lamp (MIL)

The PCM illuminates the MIL (service engine soon or check engine) in the DIC 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.

Park Brake Indicator

PARK BRAKE

The PARK BRAKE indicator illuminates in the DIC when the following occurs:

    • The park brake is selected and the park brake switch closes (signal circuit is low).
    • The displays test is performed in the IPC at the beginning of each ignition cycle. The indicator illuminates for approximately 3 seconds.

Reduced Engine Power Indicator

The REDUCED ENGINE POWER indicator illuminates in the DIC when the PCM detects a malfunction in the throttle actuator control (TAC) system. The PCM grounds the reduced engine power indicator control circuit.

Throttle System Indicator

SERVICE THROTTLE SOON

The PCM illuminates the SERVICE THROTTLE SOON indicator in the DIC when it detects a malfunction in the throttle system. The PCM grounds the service throttle soon indicator control circuit.

Transmission Indicator

SERVICE TRANS FILTER

The SERVICE TRANS FILTER indicator illuminates in the DIC when the transmission oil filter differential switch detects a pressure differential increase of approximately 6 psi (41 kPa). The transmission oil differential switch grounds the service trans filter indicator control circuit.

Wait To Start Indicator (Diesel Engine Only)

The WAIT TO START indicator illuminates in the DIC as determined by the PCM. The PCM provides power to illuminate the indicator via the wait to start indicator control circuit. The indicator illuminates with the ignition ON and the engine OFF.