Module, Instrument Panel Cluster (IPC): Operation: Notes

The Instrument Panel Cluster (IPC) is designed to allow the vehicle operator to monitor the conditions of many of the vehicle components and operating systems. The gauges and indicators in the IPC provide valuable information about the various standard and optional powertrains, fuel and emissions systems, cooling systems, lighting systems, safety systems and many other convenience items. The IPC is installed in the instrument panel so that all of these monitors can be easily viewed by the vehicle operator when driving, while still allowing relative ease of access for service.

The microcontroller-based IPC hardware and software uses various inputs to control the gauges and indicators visible on the face of the IPC. These inputs are in the form of electronic messages that are transmitted by other electronic modules over the Controller Area Network (CAN) data bus. Refer to COMMUNICATION, OPERATION .

The IPC microcontroller converts the input data using algorithms to provide gauge readings that are accurate, stable and responsive to operating conditions. When abnormal conditions occur, such as high coolant temperature, the algorithm will drive the gauge pointer to an extreme position and the microcontroller will sound an audible alert through the on-board audible tone transducer which provides a distinct visual and audible indication of a problem to the vehicle operator. The IPC may also produce audible warnings on behalf of other electronic modules in the vehicle based upon electronic tone request messages received over the CAN data bus. Each audible warning is intended to provide the vehicle operator with an audible alert to supplement a visual indication.

The IPC circuitry operates on battery current received through a fused B(+) circuit, and a fused ignition (RUN) circuit. This arrangement allows the IPC to provide some features regardless of the status of the ignition switch, while other features will operate only when the status of the ignition switch is ON. The IPC circuitry has a path to ground at all times through a takeout of the instrument panel wire harness that is secured to the instrument panel support structure.

The Body Control Module (BCM) stores and compares vehicle configuration data with the IPC as well as with other Electronic Control Units (ECU) in the vehicle. This process is referred to as Programming Of Configuration of Systems Integrated (PROCSI) (also known as PROXI). If a configuration mismatch is detected, the BCM will set a Diagnostic Trouble Code (DTC). A configuration mismatch will require the performance of a Restore BCM PROXI Configuration routine, or a PROXI Configuration Alignment routine using a diagnostic scan tool.

The IPC also has a self-diagnostic test capability which will test each of the CAN bus message-controlled functions of the IPC by lighting the appropriate indicators, positioning the gauge needles at several predetermined calibration points across the gauge faces and illuminating all segments of the electronic display unit. The electronic display unit will also display the software version used in the IPC. Refer to DIAGNOSIS AND TESTING .