Automatic Transmission/Transaxle: Description and Operation

Porsche Traction Management
Porsche Traction Management, or PTM, is a system which guarantees or improves the traction of the vehicle. Two controllable locks are available in the system.
It operates permanently and receives values from different sensors (e.g. steering angle sensor, lateral acceleration sensor) from which the corresponding lock controls are obtained. In this way the optimum power is distributed to the driving pinions.
The locks are:
^ Longitudinal lock (in the transfer box): Distributes the moment released by the gear via the cardan shafts to the front or rear axle gear.
^ Longitudinal interlock (depending on the equipment in the rear final drive): Distributes the moment to the two rear driving wheels.