GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2006 🢒 STS 🢒 Body 🢒 Instrument Panel, Gages, and Console 🢒 Instrument Cluster Description and Operation

Displays Test

Certain instrument panel cluster (IPC) features are tested when the ignition is turned on in order to verify that the features are working properly.

    • All gauges will perform a full sweep upon transition from CRANK to RUN.
    • The following indicators illuminate briefly at key up unless otherwise noted:
       - ABS
       - Air bag - flashes 7 times
       - BRAKE
       - Charge indicator - stays on in RUN or engine OFF
       - Coolant temp
       - Cruise - no bulb check when ACCA present
       - Fasten safety belt - flashes only if driver seatbelt unbuckled
       - Low oil pressure indicator
       - Malfunction indicator lamp (MIL)--stays on with ignition ON and the engine OFF
       - Security
       - Traction off
       - Low Tire Pressure - only with TPM equipped vehicles

Indicators and Warning Messages

Refer to Indicator/Warning Message Description and Operation.

Engine Coolant Temperature Gage

The engine control module (ECM) sends the coolant temperature to the instrument panel module (IPM) via GMLAN. The instrument panel cluster (IPC) displays the engine coolant temperature as determined by the IPM. The IPC receives a GMLAN message from the IPM indicating the engine coolant temperature. The engine coolant temperature gage, if equipped, defaults to a minimum when:

    • The ECM detects a malfunction in the engine coolant temperature sensor circuit.
    • The IPC detects a loss of GMLAN communications with the IPM.
    • The IPM detects a loss of GMLAN communications with the ECM.

Refer to Cooling System Description and Operation for more information.

Odometer

The engine control module (ECM) sends the vehicle speed information to the instrument panel cluster (IPC) via the serial data circuit. The algorithm for calculating the odometer/trip odometer and the memory for storing the odometer information is in the IPC. The odometer displays 'error' in the DIC if an internal IPC memory failure is detected, an algorithm fault is detected by the IPC or the IPC receives an invalid vehicle speed information from the ECM.

Speedometer

The engine control module (ECM) sends the vehicle speed to the instrument panel module (IPM) via GMLAN. The instrument panel cluster (IPC) displays the vehicle speed as determined by the IPM. The IPC receives a GMLAN message from the IPM indicating the vehicle speed. The speedometer will default to zero if:

    • The ECM detects a malfunction in the vehicle speed sensor circuit.
    • The IPC detects a loss of GMLAN communications with the IPM.
    • The IPM detects a loss of GMLAN communications with the ECM.

Tachometer

The engine control module (ECM) sends the engine speed to the instrument panel module (IPM) via GMLAN. The instrument panel cluster (IPC) displays the engine speed as determined by the IPM. The IPC receives a GMLAN message from the IPM indicating the engine speed. The tachometer will default to zero if:

    • The ECM detects a malfunction in the engine speed signal.
    • The IPC detects a loss of GMLAN communications with the IPM.
    • The IPM detects a loss of GMLAN communications with the ECM.