For 1990-2009 cars

Table 1: | IPC Indicators
Table 2: | DIC Indicators

#### IPC Indicators

Symbol | Description
--- | ---
| ABS: Refer to ABS Description and Operation in Antilock Brake System or to Air ABS Description and Operation in Air Antilock Brake System
APPLY PARK BRAKE | Apply Park Brake: Refer to Park Brake System Description and Operation in Park Brake
AUX BRAKE | Aux Brake: Refer to Brake Warning System Description and Operation in Hydraulic Brakes
| Charge: Refer to Charging System Description and Operation in Engine Electrical
CHECK GAGES | L18: The CHECK GAGES indicator illuminates in the IPC when one of the following occurs:

• | The PCM detects that the engine oil pressure is approximately 5 psi (34 kPa) or below.

| The PCM monitors the signal circuit of the engine oil pressure sensor.

• | The PCM detects that the engine coolant temperature is approximately 107°C (225°F) or above.

| The PCM monitors the signal circuit of the engine coolant temperature sensor.

The PCM grounds the check gages indicator control circuit in order to illuminate the CHECK GAGES indicator.

The MFAM receives a direct hardwire input from the PCM and the engine will be shutdown, on vehicles equipped with automatic engine shutdown, when one of the following conditions exist:

• | The PCM detects that the engine coolant temperature is at or above 111° C (232° F).

• | The PCM detects that the engine oil pressure is at or below 34 kPa (5 psi).

The MFAM grounds the stoplamp switch signal circuit in order to shut the engine down.

LG5: The CHECK GAGES indicator illuminates in the IPC when one of the following occurs:

• | The MFAM detects that the engine oil pressure is approximately 5 psi (34 kPa) or below.

| The MFAM monitors the signal circuit of the engine oil pressure switch.

• | The MFAM detects that the engine coolant temperature is approximately 107°C (225°F) or above.

| The MFAM monitors the signal circuit of the engine coolant temperature switch.

The MFAM grounds the check gages indicator control circuit in order to illuminate the CHECK GAGES indicator.

The engine will be shutdown, On vehicles equipped with automatic engine shutdown, when one of the following conditions exist:

• | The MFAM detects that the engine coolant temperature is at or above 111° C (232° F).

• | The MFAM detects that the engine oil pressure is at or below 34 kPa (5 psi).

The MFAM provides a ground for the stoplamp switch interface module in order to shut the engine down.

| DRL: Refer to Exterior Lighting Systems Description and Operation in Lighting Systems
| Differential Lock: Refer to Locking Differential Description and Operation in Drive Axle - Locking Limited Slip
| High Beam: Refer to Exterior Lighting Systems Description and Operation in Lighting Systems
INTAKE HEATER | Intake Heater: Refer to the Cat© Medium Duty Diesel Manual - LG 5
| Low Air Brake Pressure: Refer to Brake Warning System Description and Operation in Air Brakes
LOW COOLANT | Low Coolant: Refer to Cooling System Description and Operation in Engine Cooling
PARK BRAKE | Park Brake: Refer to Park Brake System Description and Operation in Park Brake
PRIMARY BRAKE | Primary Brake: Refer to Brake Warning System Description and Operation in Hydraulic Brakes
SERVICE ENGINE SOON | Malfunction Indicator Lamp (MIL): Refer to Powertrain Control Module Description in Engine Controls - 8.1 L or to the Cat© Medium Duty Diesel Manual - LG 5
SERVICE PARK BRAKE | Service Park Brake: Refer to Park Brake System Description and Operation in Park Brake
| Turn Signals: Refer to Exterior Lighting Systems Description and Operation in Lighting Systems

#### DIC Indicators

Symbol | Description
--- | ---
CHANGE OIL | The CHANGE OIL indicator illuminates in the driver information center (DIC) when the powertrain control module (PCM) determines that the engine oil should be changed. The PCM provides a ground for the change oil indicator control circuit in order to illuminate the CHANGE OIL indicator. After the oil is changed, reset the engine oil monitor. Refer to GM Oil Life System Resetting in Maintenance and Lubrication.
| The Check Transmission indicator illuminates in the DIC when the transmission control module (TCM) detects certain malfunctions in the transmission. The TCM grounds the check trans indicator control circuit in order to illuminate the Check Transmission indicator.
ENGINE OVERSPEED | The ENGINE OVERSPEED indicator illuminates in the DIC when the PCM detects that the engine speed range is between 3,600 and 4,000 RPM. The PCM grounds the engine overspeed indicator control circuit in order to illuminate the ENGINE OVERSPEED indicator.
| The fasten safety belt indicator illuminates in the DIC, for approximately 8 seconds, when the seat belt alarm module detects that the ignition transitions to ON. The seat belt alarm module supplies voltage to the seat belt indicator voltage circuit in order to illuminate the fasten safety belt indicator.
REDUCED ENGINE POWER | The REDUCED ENGINE POWER indicator illuminates in the DIC when the PCM detects a malfunction in the throttle actuator control system. The PCM grounds the reduced engine power indicator control circuit in order to illuminate the REDUCED ENGINE POWER indicator.
SERVICE TRANS FILTER | The SERVICE TRANS FILTER indicator illuminates in the DIC when the transmission fluid filter differential switch detects a pressure differential increase of approximately 41 kPa (6 psi). The transmission fluid filter differential switch grounds the service trans filter indicator control circuit in order to illuminate the SERVICE TRANS FILTER indicator.
| Trailer ABS: Refer to Air ABS Description and Operation in Air Antilock Brake System