Operation - RHD: Notes
Indicators are located in various positions within the Instrument Cluster, and are all connected to the electronic circuit board. Some indicators operate based upon hard-wired inputs to the cluster, but most are controlled by Controller Area Network (CAN) or Local Interface Network (LIN) data bus messages from other electronic modules in the vehicle. Some are controlled by a combination of hard-wired inputs, electronic messaging and cluster programming. If the instrument cluster loses CAN data bus communication, the cluster circuitry will automatically turn ON the Malfunction Indicator Lamp (MIL) until CAN data bus communication is restored. If the cluster looses CAN data bus communication with the Totally Integrated Power Module (TIPM), all of the modules that are supported by the CAN C data bus will illuminate the appropriate cluster tell tail warnings.
The various indicators are controlled by different strategies; some receive fused ignition switch output from the instrument cluster circuitry and have a switched ground, while others are grounded through the instrument cluster circuitry and have a switched battery feed. However, all indicators are completely controlled by the instrument cluster microprocessor based upon various hard-wired and electronic message inputs. The cruise indicator located within the odometer Vacuum-Florescent Display (VFD) unit is dimmable. All other indicators are illuminated at a fixed intensity, which is not affected by the selected illumination intensity of the instrument cluster general illumination lighting. The illumination intensity of the dimmable indicator is synchronized with that of the general illumination lighting.
In addition, certain indicators in this instrument cluster are automatically or self-configured. This feature allows the configurable indicators to be enabled by the instrument cluster circuitry for compatibility with certain optional equipment. These indicators are enabled or disabled by an electronic configuration message sent to the instrument cluster by the TIPM. The TIPM defaults for the Anti-Lock Brake System (ABS) indicator and airbag indicator are enabled, and these configuration settings must be programmatically disabled in the TIPM using a diagnostic scan tool for vehicles that do not have this equipment. The automatically or self-configured indicators remain latent in each instrument cluster at all times and will be active only when the instrument cluster receives the appropriate CAN or LIN bus message inputs for that optional system or equipment.
Hard-wired circuitry connects the instrument cluster to the electrical system of the vehicle. These hard-wired circuits are integral to several wire harnesses, which are routed throughout the vehicle and retained by many different methods. These circuits may be connected to each other, to the vehicle electrical system and to the instrument cluster through the use of a combination of soldered splices, splice block connectors, and many different types of wire harness terminal connectors and insulators. Refer to the appropriate wiring information. The wiring information includes wiring diagrams, proper wire and connector repair procedures, further details on wire harness routing and retention, as well as pin-out and location views for the various wire harness connectors, splices and grounds.
The hard-wired indicator inputs may be diagnosed using conventional diagnostic tools and procedures. However, the instrument cluster circuitry and electronic CAN or LIN data bus message controlled indicators are diagnosed using the instrument cluster self-test. Refer to DIAGNOSIS AND TESTING . Proper testing of the CAN or LIN data bus and the electronic data bus message inputs to the instrument cluster that control each indicator requires the use of a diagnostic scan tool. Refer to the appropriate diagnostic information.