Description And Operation: Operation

WARNING: This page is about a different car, the 2020 Jeep Renegade. However, it is still accessible from the selected car via links, so may be relevant.

The Power Transfer Unit (PTU) engages and disengages the propeller shaft as requested by the DTCM. The DTCM receives information from other modules via Controller Area Network (CAN) bus, such as the gear engaged, engine load, vehicle speed, the drive mode requested by the operator, and others, to determine when to engage or disengage the propeller shaft on the basis of the most appropriate strategy. The DTCM controls an actuator installed on the PTU to transmit torque to the propeller shaft.

In "AUTO" mode, (DTCM) controls the Power Transfer Unit (PTU) actuator so that when starting from a standstill or speeds close to 0 km/h (0 mph) the propeller shaft is always engaged. When the vehicle speed exceeds a set threshold, the engine load is not too high and the road conditions are ideal, the DTCM will command the PTU actuator to disengage the propeller shaft for the purposes of saving fuel. The conditions for which the DTCM re-engages the propeller shaft are, for example:

If the road features irregular surfaces that compromises the dynamics/safety of the vehicle.
If the vehicle speed returns to close to 0 km/h (0 mph).

The propeller shaft is disengaged only if the Select Terrain selector is in AUTO mode and only at a specific speeds in order not to compromise driving safety.

In TRACTION mode, the DTCM commands the PTU actuator so that the propeller shaft is always engaged.

In SPORT mode, the DTCM commands the PTU actuator so that the propeller shaft is always engaged.

In the case of system or selector faults, the mode change option will be automatically disabled. The system will automatically set itself to AUTO mode. In these cases the display will show a dedicated warning. The DTCM has the capability of storing Diagnostic Trouble Codes (DTCs) that can be read using an appropriate diagnostic scan tool to aid in diagnosing the system.