Check Gauges Lamp

The check gauges lamp gives an indication when certain gauges reflect a condition requiring immediate attention. The lamp is turned on by the instrument cluster circuitry for about three seconds after the ignition switch is turned to the On position as a bulb test. After the bulb test, the lamp is controlled by the instrument cluster circuitry based upon gauge data messages received from the Powertrain Control Module (PCM) on the Chrysler Collision Detection (CCD) data bus.

The PCM uses several inputs to decide what gauge data messages are required. The PCM then sends the proper message to the instrument cluster on the CCD data bus. When the instrument cluster circuitry receives a gauge data message that requires the check gauges lamp to be turned on, it also sends a chime tone request to the Central Timer Module (CTM).

The gauge data messages for which the instrument cluster is programmed to turn on the check gauges lamp are:
- Engine coolant temperature is high
- Engine oil pressure is low
- System voltage is high or low.