Heat Protection - Rear Drive Unit (RDU)

During aggressive on road driving, the AWD system may implement a heat protection mode to protect the AWD clutch from damage. Without power transfer unit or Rear Drive Unit (RDU) temperature sensors, the PCM performs calculations to determine the need for the heat protection mode. If the AWD system detects an overheat condition, it enters a locked mode. If the heat in the Rear Drive Unit (RDU) continues to rise once in the locked mode, the PCM disables the Active Torque Coupling (ATC) solenoid. This condition may be indicated by an AWD Temporarily Disabled message or AWD OFF message in the message center. To resume normal operation, stop the vehicle in a safe location and turn the engine off for at least 10 minutes. After the engine is restarted and the AWD system has adequately cooled down, the AWD Temporarily Disabled message turns off and normal AWD operation returns. In the event the engine is not stopped, the AWD Temporarily Disabled message turns off when the system cools. Normal AWD operation returns once the message center displays AWD Restored or AWD OFF message disappears.

The utility police interceptor with a 3.5L GTDI engine may be equipped with an optional PTU cooling system. The PTU cooling system consists of a PTU fluid pump and cooler. When PTU fluid temperature reaches 125 deg. C (257 deg. F) the cooling pump is activated and continues operating until the temperature reaches 100 deg. C (212 deg. F).