Durango 4WD V8-5.9L VIN Z (1998)
Temperature Warning Lamp/Indicator: Description and Operation
SYSTEM OPERATION
Transmission Oil Temperature Warning Lamp
The transmission oil temperature warning lamp gives an indication when the Powertrain Control Module (PCM) has detected that the automatic
transmission oil is overheated. The lamp is controlled by the instrument cluster circuitry based upon messages received from the PCM on the
Chrysler Collision Detection (CCD) data bus. The PCM sends lamp-on messages for about two seconds when the ignition switch is turned to the
On position as a bulb test.
Following the bulb test, the PCM uses an input from the automatic transmission oil temperature sensor located within the transmission, along with
its internal programming, to decide whether a condition exists that requires the transmission oil temperature warning lamp to be turned on. The
PCM then sends the proper messages to the instrument cluster on the CCD data bus to turn the lamp on or off. When the instrument cluster
receives a message to turn the transmission oil temperature warning lamp on, it also sends a chime tone request to the Central Timer Module
(CTM).
