Power, Ground and Class 2
The instrument panel cluster (IPC) receives battery positive voltage from the instrument panel (IP) fuse block CLSTR fuse, through CKT 1440 to terminal G. The IPC receives ignition voltage (ACCY and ON) from the IP fuse block BCM/CLU fuse, through CKT 39 to terminal J.
The IPC receives ground from CKT 150 to terminal A and from CKT 451 to terminal H.
The IPC receives all class 2 serial data messages on CKT 1807 at terminal L and terminal K.
Indicators
The IPC uses the class 2 serial data to light the various indicators and control the gauges. The THEFT SYSTEM indicator and SERVICE ENGINE SOON indicators are the only discrete inputs to the IPC. CKT 728 from the body control module (BCM) to the IPC terminal E controls the THEFT SYSTEM indicator. CKT 419 from the powertrain control module (PCM) to the IPC terminal D controls the SERVICE ENGINE SOON indicator.
The left turn indicator is controlled through CKT 14 to terminal F of the IPC. The right turn indicator is controlled through CKT 15 to terminal C of the IPC.
Engine Coolant Temperature Gage
The powertrain control module (PCM) sends coolant temperature as determined by the coolant temperature sensor to the body control module (BCM) via class 2. The instrument panel cluster (IPC) displays the engine coolant temperature as determined by the BCM. The IPC receives a class 2 message from the BCM indicating the engine coolant temperature. The engine coolant temperature gage defaults to 75°C (160°F) or below if:
| • | The PCM detects a malfunction in the engine coolant temperature sensor circuit. |
| • | The IPC detects a loss of class 2 communications with the BCM. |
| • | The BCM detects a loss of class 2 commumications with the PCM. |
Fuel Gage
The powertrain control module (PCM) sends fuel level percent to the body control module (BCM) via class 2. The instrument panel cluster (IPC) displays the fuel level as determined by the BCM. The IPC receives a class 2 message from the BCM indicating the fuel level percent. The fuel gage defaults to E (empty) if:
| • | The PCM detects a malfunction in the fuel level sensor circuit. |
| • | The IPC detects a loss of class 2 communications with the BCM. |
| • | The BCM detects a loss of class 2 commumications with the PCM. |
When the fuel level is less than 4%, the CHECK GAGES indicator illuminates.
Odometer
The instrument panel cluster (IPC) contains a season odometer and a trip odometer. Momentarily press the trip/reset switch on the IPC in order to toggle between the season odometer and the trip odometer. Press the trip/reset switch for greater than 2 seconds, while the trip odometer is displayed, in order to reset the trip odometer. The IPC displays the vehicle mileage and trip mileage as determined by the body control module (BCM). The BCM calculates the mileage based on the vehicle speed signal circuit from the PCM. The odometer will display 'error' if an internal IPC memory failure is detected or there is a loss of class 2 communication.
Speedometer
The instrument panel cluster (IPC) displays the vehicle speed based on the information from the body control module (BCM). The BCM receives a class 2 message from the powertrain control module (PCM) indicating the vehicle speed. The PCM calculates the vehicle speed based on the class 2 message indicating the wheel reference speed from the electronic brake control module (EBCM) if:
| • | The PCM detects a malfunction in the vehicle speed sensor circuit. |
| • | The IPC detects a loss of class 2 communications with the BCM. |
The speedometer defaults to 0 km/h (0 mph) if the BCM detects a loss of class 2 communications with both the PCM and the EBCM.
Tachometer
The instrument panel cluster (IPC) displays the engine speed as determined by the body control module (BCM) via a class 2 message. The BCM receives a class 2 message from the powertrain control module (PCM) indicating the engine speed. The tachometer will default to 0 RPM if:
| • | The PCM detects a malfunction in the engine speed sensor circuit. |
| • | The IPC detects a loss of class 2 communications with the BCM. |
| • | The BCM detects a loss of class 2 communications with the PCM. |
