Instrument Cluster Illumination
The instrument cluster has 2 front flood illumination lamps and 4 rear back-lighting lamps. The signal to control these instrument cluster illumination lamps is a pulse width modulated voltage driven by the body control module (BCM).
The BCM varies the duty cycle based on the position of instrument panel dimmer knob. The duty cycle varies from approximately 20 percent LO to 100 percent HI. The BCM also sends class 2 messages to the cluster, to control odometer backlighting brightness, based on the position of the instrument panel dimmer knob.
Instrument Panel I/P Cluster Telltales
| Telltale Gage or Lamp | Input To BCM | Input To Cluster | ||
|---|---|---|---|---|
| Direct Wire | Serial Data | Direct Wire | Serial Data | |
| ABS | EBTCM | - | - | BCM |
| Low Traction | EBTCM | - | - | BCM |
| Air Bag | - | - | - | SDM |
| Brake | X | - | - | BCM |
| Hot Coolant | - | ECM | - | BCM |
| DRL | X | - | - | BCM |
| Charging System | - | ECM | - | BCM |
| High Beam Lamp | X | - | - | BCM |
| Left Turn Lamp | - | - | X | - |
| Low Brake Fluid | X | - | - | BCM |
| Low Coolant | X | - | - | BCM |
| Low Fuel | - | ECM | - | BCM |
| Washer Fluid Low | X | - | - | BCM |
| Service Engine Soon | - | ECM | - | BCM |
| Change Oil Soon | - | ECM | - | BCM |
| Oil Pressure | - | ECM | - | BCM |
| Reduced Power | - | ECM | - | BCM |
| Right Turn Lamp | - | - | X | - |
| Seat Belt | - | - | - | SDM |
| Security | X | - | BCM | - |
| Service Wrench | - | ECM | - | BCM |
| Decklid/Lift Gate Ajar | X | - | - | BCM |
| Speedometer | - | ECM | - | BCM |
| Odometer | - | ECM | - | BCM |
| Tachometer | - | ECM |
- | BCM |
| Fuel Gage | - | ECM | - | BCM |
| Coolant Gage | - | ECM | - | BCM |
| Illumination Lamps | Direct wire from BCM | |||