Gauge Pack, Instrument Cluster: Operation: Operation: Gauges: Notes

All gauges receive battery current through the Instrument panel Cluster (IPC) circuitry only when the ignition switch is in the ON or START positions. With the ignition switch in the OFF position battery current is not supplied to any gauges, and the IPC circuitry is programmed to move all of the gauge needles back to the low end of their respective scales. Therefore, the gauges do not accurately indicate any vehicle condition unless the ignition switch is in the ON or START positions.

Only the Tachometer and the Speedometer of the IPC are driven by stepper motors. Two fixed electromagnetic coils are located within each gauge. These coils are wrapped at right angles to each other around a movable permanent magnet. The movable magnet is suspended within the coils on one end of a pivot shaft, while the gauge needle is attached to the other end of the shaft. One of the coils has a fixed current flowing through it to maintain a constant magnetic field strength. Current flow through the second coil changes, which causes changes in its magnetic field strength. The current flowing through the second coil is changed by the IPC circuitry in response to messages received over the CAN data bus. The gauge needle moves as the movable permanent magnet aligns itself to the changing magnetic fields created around it by the electromagnets. Unlike the tachometer and the speedometer, the fuel level gauge and the engine temperature gauges are electronic bar graph gauges located within the Electronic Vehicle Information Center (EVIC).