Electro-Mechanical Instrument Cluster Module

There are 4 different instrument clusters. Base, premium, luxury, and AutoStick. The premium cluster is equipped with a tachometer and a low fuel indicator. The luxury cluster has the same features as the premium cluster with an additional black overlay and chrome rings. The AutoStick cluster is the luxury cluster with the AutoStick function. The transmission controller (TCM) controls the Vacuum Fluorescent (VF) PRND or Auto-Stick display. The cluster will illuminate the appropriate PRND or gear position based on PCI Bus data received from the TCM.

The cluster speedometer, tachometer, and engine coolant temperature gauges are positioned using PCI Bus messages received from the PCM. The fuel gauge is a hard wired input from the fuel level sensor in the fuel pump module.

The cluster also contains warning indicators that are illuminated by hard wired inputs or by messages received from other modules on the PCI Bus.

The Trip/Total Odometer is a Vacuum Fluorescent (VF) display that is controlled by PCI Bus messages received from the PCM. The VF display also displays the Door, Cruise, and Trac messages. If the cluster experiences a loss of PCI Bus communication with other modules on the Bus, the cluster will display "nobuS" in the VF display.

The illumination lamps are hard wired in the cluster. When the park or headlamps are turned on, the cluster receives a hard wire input from the multi-function switch. The cluster sends a panel lamps dimmer signal to ground through the multi-function switch. The varying voltage drop is sensed by the instrument panel drivers to create a corresponding amount of illumination dimming. This dimming level is then sent out from the cluster to other components.

The cluster will communicate with the DRBIII to display PCI engine info, PCI Bus info, and certain inputs/outputs. The cluster is also capable of performing a diagnostic self-test that is actuated by depressing and holding the odometer trip reset stalk while cycling the ignition from the off to the on position. The cluster will position all of the gauges at specified calibration points and will illuminate all the PCI Bus controlled indicators. The cluster will also illuminate each segment of the VF display.

If the cluster does not detect voltage on the courtesy lamp circuit, the message FUSE will alternate with the odometer/trip odometer for 30 seconds after the ignition is turned on and for 15 seconds after the vehicle is first moved.