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

All gauges receive battery current through the Instrument Cluster (IC) circuitry; only when the ignition switch is in the ON or START positions. With the ignition switch in the OFF position the cluster 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.

All of the gauges 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 cluster circuitry in response to messages received over the CAN data bus from the Body Control Module (BCM). The gauge needle moves as the movable permanent magnet aligns itself to the changing magnetic fields created around it by the electromagnets.