Volt Meter Gauge: Description and Operation

SYSTEM OPERATION
The voltmeter gives an indication of the electrical system voltage. The instrument cluster circuitry controls the gauge pointer position. The instrument cluster circuitry calculates the proper gauge pointer position based upon system voltage messages received from the Powertrain Control Module (PCM) on the Chrysler Collision Detection (CCD) data bus.

The PCM uses an input from the electrical system and internal programming to decide what system voltage messages are required. The PCM then sends the proper messages to the instrument cluster on the CCD data bus. If the PCM messages indicate that the charging system has failed, the electrical system voltage is less than 11 volts or greater than 16.6 volts, the instrument cluster circuitry turns on the Check Gauges lamp and sends a chime tone request to the Central Timer Module (CTM). Refer to Starting and Charging/Charging Systems for more information on the charging system components and their diagnosis.