Instrument Cluster

Mechanical Instrument Cluster (MIC) is divided into 4 parts as follows:

• Hard wired indicator lights.
• PCI bus indicator lights.
• Primary gauges (speedometer and tachometer).
• Secondary gauges (fuel level, oil pressure, coolant temperature and charging voltage).

Powertrain Control Module (PCM) sends signals necessary for instrument cluster to position gauges. Instrument cluster receives these messages from bus and translates them into gauge positions when ignition switch is in RUN or START positions. BCM sends status of all indicator lights and dimming level to instrument cluster over bus when ignition switch is in RUN or START positions. Malfunction indicator light (CHECK ENGINE) status is sent to instrument cluster from PCM over bus.

A bulb check is performed when ignition switch is in RUN position consisting of most bus controlled indicator lights being activated for approximately 2 to 4 seconds. Vacuum florescent odometer/trip display works when ignition switch is in RUN or START positions. BCM stores mileage information for odometer. BCM sends mileage message and dimming level message to vacuum fluorescent display when ignition switch is in the RUN position. If bus is not functioning, odometer will display dashes instead of the mileage. All other instrument cluster features only work when the ignition switch is in the RUN position.