Diagnosis/troubleshooting PSM 5.7

NOTE: If the fault codes 4400 Transverse acceleration sensor, 4420 Rate-of-turn sensor and 4440 Steering-angle sensor are displayed together, there may be an open circuit in the circuit to control module terminal 39.

Rate-of-turn sensor is combined with the transverse acceleration

Fig 1: Identifying Rate-Of-Turn Sensor Combined With Transverse Acceleration

Courtesy of PORSCHE OF NORTH AMERICA, INC.

DIAGNOSIS/TROUBLESHOOTING PSM 5.7 (FAULT CODE 4400)

Work instruction			Display OK	If not OK
1	Check lead from PSM control module to transverse acceleration sensor for short circuit to ground/open circuit	Switch off ignition Pull plug off transverse acceleration sensor (rate-of-turn sensor) Switch on ignition Measure voltage between pin 3 of transverse acceleration sensor (rate-of-turn sensor) plug and ground	>11 V Step 2	Short circuit to ground/open circuit in electric circuit between PSM control module plug pin 39 and plug of transverse acceleration sensor (rate-of-turn sensor) pin 3 or PSM control module is faulty ->End
2	Check ground lead of the transverse acceleration sensor for open circuit	Measure voltage between pin 3 of the transverse acceleration sensor (rate-of-turn sensor) plug and pin 6 of the transverse acceleration sensor (rate-of-turn sensor) plug	>11 V Step 3	Open circuit in circuit between PSM control module plug pin 21 and pin 6 of the transverse acceleration sensor (rate-of-turn sensor) plug, or PSM contol module faulty ->End
3	Check signal lead of the transverse acceleration sensor for short circuit to B+	Switch off ignition Pull off the PSM control module plug Switch on ignition Measure voltage between PSM control module plug pin 8 and ground	< 0.3V Step 4	Short circuit to B+ between PSM control module plug pin 8 and pin 5 of the transverse acceleration sensor (rate-of-turn sensor) plug ->End
4	Check signal lead of the transverse acceleration sensor for short circuit to ground	Switch off ignition Measure resistance between PSM control module plug pin 8 and ground	Step 5	Short circuit to ground between PSM control module plug pin 8 and pin 5 of the transverse acceleration sensor (rate-of-turn sensor) plug ->End
5	Check signal lead of the transverse acceleration sensor for open circuit	Measure resistance between PSM control module plug pin 8 and pin 5 of the transverse acceleration sensor (rate-of-turn sensor) plug	< 5 Step 6	Open circuit between PSM control module plug pin 8 and pin 5 of the transverse acceleration sensor (rate-of-turn sensor) plug ->End
6	Transverse acceleration sensor (rate-of-return sensor) faulty		->End