Engine Coolant Temperature Gauge

The Power Control Module (PCM) via the class II serial data line to the instrument cluster, broadcasts the coolant temperature. The instrument cluster compares the temperature data using a 16 point look-up table in order to determine the needle deflection. A smooth filter is used in order to secure a continuous response. The instrument cluster drives the temperature gauge to C (cold) under the following conditions:
^ The temperature data is lost.
^ The PCM is in a state of health fault.