Porsche Stability Management - Diagnosis/Repair
Cayenne14/04 4562
Binder - 4, Running Gear
Date: 10-15-04
Porsche Stability Management (PSM) Repair and Diagnosis
Vehicle Type:
Cayenne/Cayenne S/Cayenne Turbo
Model Year:
'03 (3) and '04 (4)
Concerns:
PSM (Porsche Stability Management) repair and diagnosis of customer complaints.
Information:
The activated PSM light with the "PSM failure workshop" display has caused unnecessary replacement of PSM control units. Porsche AG technical evaluation of the returned PSM control units has shown that a large percentage of the returned PSM control units were not defective.
For this reason, we have published the following list of work procedures for PSM issues.
Following these work procedures should help eliminate the unnecessary replacement of PSM control units.
It should also be noted that the PSM light has a double-function:
- PSM light flashes
The system is currently active. Flashing indicates a control intervention. No message is indicated in the multi-function display of the instrument cluster.
- PSM light is lit continuously
a) The system is free of faults if the message "PSM switched off" appears in the multi-function display of the instrument cluster and the PSM push-button lights up yellow.
b) The system has failed if the message "PSM failure workshop" appears in the multi-function display of the instrument cluster.
Tools:
PIWIS Tester
Work Procedure:
Repair instructions for defects in the PSM (Porsche Stability Management)
1. Connect charger to the electrical system battery and switch on.
2. Switch on ignition.
3. Connect PIWIS Tester to the diagnosis connector according to Workshop Manual, Group 0, Diagnosis and read out all fault memories.
- If there are no fault entries, continue with Step 14.
- If there are fault entries for the steering-angle sensor, continue with Step 4.
- If there are fault entries for other control units, continue with Step 5.
- If there are fault entries for PSM sensors/actuators, continue with Step 6.
- If there is a "PSM control unit faulty" fault entry, continue with Step 7.
4. Complaint - Fault entries for the steering-angle sensor.
Note:
No replacement of PSM control unit necessary! Remedy: See work procedure, Steps 4.1/4.2/4.3/4.4/4.5
4.1 The fault entry "Steering-angle sensor, mechanically faulty" is displayed after reading out the fault memory in the PIWIS Tester.
4.1.1 Carry out a diagnosis of the steering-column switch according to Workshop Manual, Diagnosis, Chapter 9450.
4.1.2 Replace the steering-column switch depending on the diagnosis result according to Workshop Manual, Group 9, Chapter 94 50 19 and calibrate the steering-angle sensor according to Workshop Manual, Group 4, Chapter 45 60.
4.1.3 Continue with procedure, Step 4.5.
4.2 The fault entry "Steering-angle sensor, no signal/communication" is displayed after reading out the fault memory in the PIWIS Jester.
4.2.1 Carry out a diagnosis of the steering-column switch according to Workshop Manual, Diagnosis, Chapter 9450.
4.2.2 Check power supply of steering-column switch according to Workshop Manual, Diagnosis
4.2.3 Carry out a line test of the steering-column switch/CAN according to Workshop Manual, Diagnosis, Chapter 97.
4.2.4 Replace the steering-column switch depending on the diagnosis result according to Workshop Manual, Group 9, Chapter 94 50 19 and calibrate the steering-angle sensor according to Workshop Manual, Group 4, Chapter 45 60.
4.2.5 Continue with work procedure, Step 4.5.
4.3 The steering-angle sensor is not initialized if the fault entry "Steering-angle sensor, no fault status available" is displayed in the PIWIS Tester. It is planned that the correct fault entry "Steering- angle sensor not initialized" will be displayed in the PIWIS Tester as of test software version 7.0.
4.3.1 Initialize the steering-angle sensor according to Workshop Manual, Group 4, Chapter 45 60.
4.3.2 Continue with work procedure, Step 4.5.
4.4 The fault entry "Steering-angle sensor, not calibrated" is displayed after reading out the fault memory in the PIWIS Tester.
4.4.1 Calibrate the steering-angle sensor according to Workshop Manual, Group 4, Chapter 45 60.
4.4.2 Continue with work procedure, Step 4.5.
4.5 Using the PIWIS Tester, select "Steering-angle" under actual values in the "PSM" control unit menu and move the steering wheel in both directions.
If values change plausibly, continue with work procedure, Step 8.
If values do not change plausibly, continue with procedure, Step 3 and read out the fault memory again.
5. Complaint - Fault entries that refer to other control units.
Note:
No replacement of PSM control unit necessary!
Remedy: See work procedure, Steps 5.1/5.2/5.3
Information: If there are fault entries that refer to other control units, there is no fault in the PSM system. The reason for the fault entry and the PSM system switching off is a fault in the displayed system or a communication problem between the two systems.
5.1 The fault entry "Control unit , please read out fault memory" is displayed after reading out the fault memory in the PIWIS Tester.
5.1.1 Carry out diagnosis of displayed control unit according to Workshop Manual, Diagnosis and remedy the fault of the displayed system.
5.1.2 Continue with work procedure, Step 8.
5.2 The fault entry "Control unit , no signal/communication" is displayed after reading out the fault memory in the PIWIS Tester.
5.2.1 Carry out diagnosis of displayed control unit according to Workshop Manual, Diagnosis and remedy the fault in the displayed system.
5.2.2 Check power supply of displayed control unit according to Workshop Manual, Diagnosis.
5.2.3 Carry out a line test of the displayed control unit/CAN according to Workshop Manual, Diagnosis, Chapter 97.
5.2.4 If necessary, replace the displayed control unit according to the Workshop Manual.
5.2.5 Continue with work procedure, Step 8.
5.3 Multiple control units are displayed with the fault entry "No signal/communication" after reading out the fault memory in the PIWIS Tester.
5.3.1 Carry out a line test of the PSM control unit/CAN according to Workshop Manual, Diagnosis, Chapter 97.
5.3.2 Carry out a check of the CAN according to Workshop Manual, Diagnosis, Chapter 97.
5.3.3 Continue with work procedure, Step 8.
6. Complaint - Fault entries on PSM sensors/actuators.
Remedy: See work procedure, Steps 6.1 / 6.2 /6.3
Information: The electrical wires need to be checked on both sides (sensor side and control units side) for the sensors/actuators in the outer area and engine compartment. Included as part of tile PSM sensors are: ABS speed sensor, pressure sensor, way-sensor for release switch (in brake booster), combination sensor, and PSM push-button. Included as part of the PSM actuators are: booster coil (in brake booster), return pump (hydraulic pump), hydraulic unit with valves.
6.1 Check main wire harness (PSM contact plugs) and PSM control unit according to Workshop Manual, Group 9, Chapter 97 09 41 and repair if necessary.
Note:
Observe Technical Information, Group 9, No.14/04 - "PSM warning light in instrument cluster is activated"
6.2 Check the affected sensors/actuators.
Note:
While doing this, always also check the affected wires (for open circuit, short to ground, and short circuit to B+) and the associated plug connections (for corrosion and moisture).
6.2.1 Check ABS speed sensor according to Workshop Manual, Diagnosis, Chapter 45 and repair if necessary.
6.2.2 Check pressure sensor according to Workshop Manual, Diagnosis, Chapter 45 and repair it necessary.
6.2.3 Check way-sensor according to Workshop Manual, Diagnosis, Chapter 45 and repair if necessary.
6.2.4 Check release switch (in brake booster) according to Workshop Manual, Diagnosis, Chapter 45 and repair if necessary.
6.2.5 Check combination sensor according to Workshop Manual, Diagnosis, Chapter 45 and repair if necessary.
6.2.6 Check booster coil (in brake booster) according to Workshop Manual, Diagnosis, Chapter 45 and repair if necessary.
6.2.7 Check hydraulic pump according to Workshop Manual, Diagnosis, Chapter 45 and repair if necessary.
6.2.8 Check hydraulic unit with valves according to Workshop Manual, Diagnosis, Chapter 45 and repair if necessary.
6.3 Continue with work procedure, Step 8.
7. Complaint - Fault entry "PSM control module faulty" present.
Remedy: See work procedure, Steps 7.1 / 7.2 / 7.3 / 7.4
Information: For the fault entry "Control unit faulty" there is the memory status "present" and "not present". If there is an ignition reset, a sporadic control unit fault can be reset to memory status "not present" in certain circumstances. If this is the case, the control unit does not always have to be replaced.
7.1 The fault entry "Control unit faulty (memory status: present)" is displayed after reading out the fault memory in the PIWIS Tester.
7.1.1 Continue with work procedure, Step 7.4.
7.2 The fault entry "Control unit faulty (memory status: not present)" is displayed after reading out the fault memory in the PIWIS Tester.
7.2.1 Erase fault memory in the PSM control unit, switch ignition off and on, carry out a test drive (approx. 15 mm.) and then read out the fault memory again.
- If the fault entry "Control unit faulty" is displayed again after reading out the fault memory, continue with work procedure1 Step 7.4.
- If the fault entry "Control unit faulty" is no longer displayed after reading out the fault memory, continue with work procedure, Step 3.
7.3 The fault entry "Control unit faulty and fault entries on the PSM sensors/actuators" is displayed in the PIWIS Tester.
7.3.1 Remedy faults on PSM sensors/actuators according to work procedure, Step 6.
7.3.2 Erase fault memory and carry out a test drive (approx. 15 mm.).
7.3.3 Continue with work procedure, Step 3.
7.4 Replace PSM control unit according to Workshop Manual, Group 4, Chapter 45 30 19.
7.4.1 Continue with work procedure, Step 3.
8. Erase all fault memories.
9. Return to the start menu.
10. Switch off PIWIS Tester.
11. Perform a test drive.
12. Switch ignition off and then on again.
13. Connect PIWIS Tester to the diagnosis connector according to Workshop Manual, Group 0, Diagnosis and read out all fault memories.
- If there are fault entries present, continue with Step 3.
- If there are no fault entries present, continue with Step 14.
14. Return to the start menu.
15. Switch off and disconnect the PIWIS Tester.
16. Switch off the ignition.
17. Switch off the charger and disconnect.
References:
POSES, Workshop Manual, Cayenne:
> Group 0: 01 - Reading out diagnostic system fault memory and activating systems
> Group 4: 94 50 19 - Removing and installing switch for height and fore and aft adjustment for steering-column switch
45 30 19 - Removing and installing hydraulic unit (PSM control unit)
45 60 - Initializing and calibrating steering-angle sensor
> Group 9: 97 09 41 - Repairing the main wire harness (PSM contact plugs) 97 - Wiring (wiring diagrams)
POSES, Diagnostic, Cayenne:
> 45 - PSM > 94 - Diagnosis for steering-column switch
> 97 - CAN networking
POSES, Technical Information Bulletin,
Cayenne: > Group 9: Part ID. 9709 - PSM warning light is activated in instrument cluster (No.14/04)
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