Description And Operation: Operation

Indicators are located in various positions within the Instrument Panel Cluster (IPC) and are all connected to the electronic circuit board of the IPC. All hard tell-tales, except the Vehicle Theft Alarm (VTA) operate based upon hard-wired inputs to the IPC, but most are controlled by Controller Area Network (CAN) data bus messages from other electronic modules in the vehicle. If the IPC loses CAN data bus communication, the IPC circuitry will automatically turn on the Malfunction Indicator Lamp (MIL) and display No Bus in the IPC display until CAN data bus communication is restored.

The various IPC indicators are controlled by different strategies; some require fused ignition output to the IPC circuitry and have a switched ground, while others are grounded through the IPC circuitry and have a switched battery feed. However, all indicators, except the VTA are completely controlled by the IPC microcontroller based upon various hard-wired and electronic message inputs. A few, non-critical indicators are dimmable, but most indicators are illuminated at a fixed intensity, which is not affected by the selected illumination intensity of the IPC general illumination Light Emitting Diode (LED) units. The illumination intensity of the dimmable indicators is synchronized with that of the general illumination lighting.

The hard-wired indicator inputs may be diagnosed using conventional diagnostic tools and procedures. However, the IPC circuitry and electronic CAN data bus message controlled indicators are diagnosed using the self-diagnostic test. Proper testing of the CAN data bus and the electronic data bus message inputs to the IPC that control each 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.