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 with combined transverse acceleration sensor

Fig 1: Identifying Rate-Of-Turn Sensor Combined With Transverse Acceleration Sensor, PSM 5.7

Courtesy of PORSCHE OF NORTH AMERICA, INC.

DIAGNOSIS/TROUBLESHOOTING PSM 5.7 (FAULT CODE 4420)

Work instruction			Display OK	If not OK
1	Check power supply of the rate-of-turn sensor	Switch off ignition Pull plug off the rate-of-turn sensor Switch on ignition Measure voltage between pin 3 of rate-of-turn sensor plug and ground	>11 V Step 2	Open circuit in circuit between PSM control module plug pin 39 and pin 3 of the rate-of-turn sensor plug, or PSM contol module faulty ->End
2	Check ground of the rate-of-turn sensor	Measure voltage between pin 3 of the rate-of-turn sensor plug and pin 6 of the 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 rate-of-turn sensor plug, or PSM contol module faulty ->End
3	Check reference voltage of the rate-of-turn sensor	Measure voltage between pin 1 of the rate-of-turn sensor plug and pin 6 of the rate-of-turn sensor plug	approx. 2.5 V Step 4	Open circuit in circuit between PSM control module plug pin 10 and pin 1 of the rate-of-turn sensor plug, or PSM contol module faulty ->End
4	Check leads from PSM control module to rate-of-turn sensor for short circuit to B+	Switch off ignition Pull off the PSM control module plug Switch on ignition Measure voltage between pins 1, 2 and 4 of the rate-of-turn sensor plug and ground	< 0.3V Step 5	Short circuit to B+ between pins 1, 2 and 4 of the rate-of-turn sensor plug and pins 10, 9 and 41 of the PSM control module plug ->End
5	Check leads from PSM control module to rate-of-turn sensor for short circuit to ground	Switch off ignition Measure resistance between pins 1, 2 and 4 of the rate-of-turn sensor plug and ground	< 5 Step 6	Short circuit to ground between pins 1, 2 and 4 of the rate-of-turn sensor plug and pins 10, 9 and 41 of the PSM control module plug ->End
6	Check leads from PSM control module to rate-of-turn sensor for open circuit	Measure resistance between pins 1, 2 and 4 of the rate-of-turn sensor connector and pins 10, 9 and 41 of the PSM control module connector	< 5 Step 7	Open circuit between pins 1, 2 and 4 of the rate-of-turn sensor plug and pins 10, 9 and 41 of the PSM control module plug ->End
7	Check leads from PSM control module to rate-of-turn sensor for short circuit	Measure resistance between pin 1 of the rate-of-turn sensor plug and pins 2 and 4 of the rate-of-turn sensor plug Measure resistance between pin 2 of the rate-of-turn sensor plug and pin 4 of the rate-of-turn sensor plug	Step 8	Short circuit in wiring harness between pins 1, 2 and 4 of the rate-of-turn sensor plug and pins 10, 9 and 41 of the PSM control module plug ->End
8	Rate-of-turn sensor faulty		->End