Instrument Cluster / Carrier: Description and Operation

The mechanical instrument cluster is an electromechanical module which receives most of its information from the Body Control Module (BCM) via the CCD bus.

Instrument Cluster:

The cluster includes:
- 150 mph (240 km/h) speedometer
- Odometer/trip odometer and transmission range indicator with autostick transmission
- Fuel gauge
- Oil gauge
- Voltage gauge
- Temperature gauge

The warning and information indicators include the following:
- Service Engine Soon
- Airbag
- CHECK gauge
- Low fuel
- Seat belt
- Cruise
- Brake/park brake
- High beam
- Low washer fluid
- Low tire
- Vehicle Theft Security System alarm LED indicator
- Turn signals
- Pass Airbag Off

The gauges are the magnetic air-core type. When the ignition switch is OFF, the gauge pointers should rest at or below the low graduation.

INSTRUMENT PANEL DIMMING
I/P dimming is accomplished using the body computer. The panel dimming level switch is read by the body computer and converted to a value that is sent over the CCD bus.

INSTRUMENT CLUSTER (MIC)
The Prowler utilizes a 'smart' cluster similar to the cluster on Cirrus/Stratus/Breeze and Sebring convertible. The differences are the addition of an oil pressure and voltmeter gauge internal to the cluster and a new external tachometer that is mounted to the top of the steering column. There is also a new Liquid Crystal Display (LCD) odometer. This odometer is more easily read in direct sunlight. The tachometer and the voltmeter gauges are hardwired and are not part of the self test routine. They cannot be actuated. As mentioned previously, the tach is hardwired directly to the PCM, the illumination circuit, however, is part of the instrument panel lighting circuit. The voltmeter is hardwired to the B (+) circuit through the ignition switch.

As in other vehicles, the cluster positions its gauges based on a message formulated by the BCM for gauge position. All the sensors that are responsible for a gauge message are hardwired to the BCM. The BCM then builds the message and sends it over the CCD bus where the cluster will receive the message, decode it, and position all the gauge pointers at their proper positions.

The cluster also contains hardwired and CCD bus controlled warning lamps. A hardwired lamp is usually supplied B (+) by the cluster and ground by the circuit that it monitors. Any circuit that has a lamp that is CCD bus controlled will be an input to the BCM, except the Airbag Lamp which receives it's CCD messages from the Airbag Control Module (ACM). If no messages are received from the ACM for 5 seconds the Airbag lamp will be turned on.

There is an on-board self-test that can be actuated stand-alone or with the DRB. During the self-test, the cluster will position all the gauges at predetermined calibration points, the CCD controlled lamps will be illuminated, as well as the segments of the LCD odometer. This allows verification of gauge operation, CCD operation, as well as a visual check of all the individual segments in the LCD odometer.