Combination sensor

1 - Plug connection

x - Vehicle transverse axle 'transverse acceleration'

y - Vehicle direction of travel 'axial acceleration'

z - Vehicle high axle 'rate of turn/yaw speed'

Fig 1: Identifying Combination Sensor Plug Connection

Courtesy of PORSCHE OF NORTH AMERICA, INC.

NOTE:

After installing/replacing the combination sensor, the integrated sensors for axial and transverse acceleration must be calibrated using the menu with the Porsche System Tester II No. 9588.
Calibration is required in order to enter the PSM system and must only be performed when 'vehicle is positioned horizontally and brake is not actuated'.

The combination sensor is fastened to the center tunnel near the center console. The functions of the sensors listed below are integrated into the combination sensor:

Rate-of-turn sensor
Axial acceleration sensor
Transverse acceleration sensor

The combination sensor communicates (signal transfer) with the PSM control module via the separate CAN data bus 'internal CAN'.

The functions that are integrated into the combination sensor are described below:

Rate-of-turn sensor:

The rate of turn is recorded using a micromechanic system (Coriolis force). Without measurement of the rate of turn, it is not possible for the PSM control module to detect whether the vehicle is developing a tendency for spinning.¹ )

¹⁾ Coriolis force: named after the French mathematician Gustave Gaspard Coriolis (1792-1843). Coriolis force occurs in rotating systems.

Axial acceleration sensor:

Axial acceleration is measured in order to support the theoretically determined vehicle speed. In unfavorable conditions, the actual vehicle speed of four-wheel drive vehicles could not be determined reliably without the axial acceleration measurement.

Transverse acceleration sensor:

The transverse acceleration sensor supplies the PSM control module with information about the transverse accelerations occurring in the vehicle. Together with the information from the steering-angle sensor and the rate-of-turn sensor, the current vehicle handling behavior with respect to its transverse dynamics is calculated. The sensor element is a damped spring-and-mass system. Without measurement of the transverse acceleration, it is not possible for the PSM control module to detect which vehicle movements must be managed in a stable way in given road conditions.