Indicator/Warning Message Description and Operation
Indicator/Warning Message Description and Operation
The indicator description and operation uses generic indicator names. Refer to the table below for the indicators that are available on this vehicle:
ABS Indicator
The ABS indicator illuminates in the IPC when the following occurs:
* The electronic brake control module (EBCM) detects a malfunction in the ABS system.
* The displays test is performed in the IPC at the start of each ignition cycle.
Air Brake Indicator
The LOW AIR indicator illuminates in the IPC 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.
Driveline Indicator
DIFF LOCK
The DIFF LOCK indicator illuminates in the IPC when the following occurs:
* The differential lock switch air pressure increases to approximately 5 psi (34 kPa).
* The displays test is performed at the beginning of each ignition cycle. The DIFF LOCK indicator illuminates for approximately 3 seconds.
Engine Coolant Indicator
LOW COOLANT LEVEL
The multifunction alarm module illuminates the LOW COOLANT indicator in the IPC when it detects a low coolant level from the coolant level switch signal circuit. The multifunction alarm module also activates an audible warning for approximately 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 Testing and Inspection in Maintenance and Lubrication.
Engine Overspeed Indicator (Gas Engine Only)
The ENGINE OVERSPEED indicator illuminates in the DIC when the PCM detects the engine speed range is between 3,600 and 4,000 rpm. The PCM grounds the engine overspeed indicator control circuit.
Fasten Safety Belt Indicator
The safety belt indicator will illuminate in the DIC when the seat belt alarm module detects the ignition is in RUN and the seat belt is not buckled. An audible warning will sound simultaneously with the illuminated indicator for approximately 8 seconds after the ignition is placed in the RUN and the seat belt is not buckled.
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 IPC 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 IPC 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 IPC 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 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/multifunction 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) 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 Indicators
APPLY PARK BRAKE
The APPLY PARK BRAKE indicator illuminates in the IPC when the park brake module detects that the park brake is not applied with the ignition OFF. The multifunction alarm module activates an audible warning.
PARK BRAKE INDICATOR
The PARK BRAKE indicator illuminates in the IPC when the following occurs:
* The park brake control module detects that the park brake is engaged (signal is low) with the ignition ON.
* The displays test is performed at the beginning of each ignition cycle. The indicator illuminates for approximately 3 seconds.
SERVICE PARK BRAKE
The park brake control module illuminates the SERVICE PARK BRAKE indicator when it detects a malfunction in the electronic/hydraulic park brake system. The multifunction alarm module (MFAM) activates an audible warning.
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.
Shift Indicator
DO NOT SHIFT
The TCM illuminates the DO NOT SHIFT indicator in the DIC when the following occurs:
* The TCM detects a malfunction in the transmission system (signal is low).
* The TCM performs the displays test at the beginning of each ignition cycle. The indicator illuminates for approximately 3 seconds.
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.