Indicators, Instrument Cluster: Operation

Indicators are located in various positions within the Instrument Panel Cluster (IPC) and are all connected to the IPC electronic circuit board. The door ajar indicator, high beam indicator, and turn signal indicators operate based upon CAN data bus messages. The cargo lamp indicator operates based upon hardwired inputs to the IPC. The brake indicator is controlled by CAN data bus messages from the Controller Antilock Brake (CAB) as well as by hardwired park brake switch inputs to the IPC. The seat belt indicator is controlled by the Body Control Module (BCM) programming, CAN data bus messages from the Occupant Restraint Controller (ORC), and a hardwired seat belt switch input to the BCM. The Malfunction Indicator Lamp (MIL) is normally controlled by CAN data bus messages from the PCM; however, if the IPC loses CAN data bus communication, the IPC circuitry will automatically turn the MIL ON until CAN data bus communication is restored. The IPC uses CAN data bus messages from the BCM, the ORC, the CAB, and the Wireless Ignition Node to control all of the remaining indicators.

The various IPC indicators are grounded through the IPC circuitry and have a switched battery feed. All indicators are completely controlled by the IPC microcontroller based upon various hardwired and electronic message inputs. The cruise, four-wheel drive, four-wheel drive auto, four-wheel drive low, overdrive OFF and tow/haul indicators and those located within the LCD unit are dimmable. All other indicators are illuminated at a fixed intensity, which is not affected by the selected illumination intensity of the IPC general illumination lamps. The illumination intensity of the dimmable indicators is synchronized with that of the IPC general illumination lamps.

In addition, certain indicators in this instrument cluster are automatically or self-configured. This feature allows the configurable indicators to be enabled by the IPC circuitry for compatibility with certain optional equipment. The IPC defaults for the ABS indicator and airbag indicator are enabled, and these configuration settings must be programmatically disabled in the IPC using a diagnostic scan tool for vehicles that do not have this equipment. The automatically or self-configured indicators remain latent in each IPC at all times and will be active only when the IPC receives the appropriate CAN bus message inputs for that optional system or equipment.

The hardwired indicator inputs may be diagnosed using conventional diagnostic tools and procedures. However, the IPC circuitry and CAN bus message controlled indicators are diagnosed using the IPC self-diagnostic test. Refer to DIAGNOSIS AND TESTING . Proper testing of the CAN data bus and the electronic data bus message inputs to the IPC that control an indicator requires the use of a diagnostic scan tool. Refer to the appropriate diagnostic information. Specific details of the operation for each indicator may be found elsewhere in this service information.