Temperature Gauge: Description and Operation

ENGINE COOLANT TEMPERATURE GAGE
The IPC displays the engine coolant temperature as determined by the PCM. The IPC receives a class 2 message from the PCM indicating the engine coolant temperature. The engine coolant temperature gage defaults to 75°C (160°F) or below when:
^ The PCM detects a malfunction in the engine coolant temperature sensor circuit.
^ The IPC detects a loss of class 2 communication with the PCM.

TRANSMISSION TEMPERATURE GAGE
The IPC displays the transmission temperature as determined by the PCM. The IPC receives a class 2 message from the PCM indicating the transmission temperature. The transmission temperature gage will default to 40°C (100°F) or below if:
^ The PCM detects a malfunction in the transmission temperature sensor circuit.
^ The IPC detects a loss of class 2 communications with the PCM.