Antilock Brakes / Traction Control Systems: Application and ID
PSMIntroduction
Porsche Stability Management (PSM)
Diagnosis software number: PSM 0101
Cayenne model year 2003
General instructions/safety instructions
WARNING:
Danger of damage due to improper handling of batteries and control module plug connections.
- Never disconnect battery with engine running.
- Never start engine if battery terminal clamps are not connected securely.
- Never pull off or push on plug connections for the control modules or other electronic components when the ignition is switched on.
- Always disconnect the negative terminal of the battery and pull off all plug connections to the vehicle electrical system control module when carrying out welding work on the vehicle.
WARNING:
Danger of injury and damage as a result of the vehicle's unusual handling behavior caused by disconnected plugs or components.
- Never disconnect plugs while driving or drive with them disconnected.
- Drive only with fully installed and connected parts.
WARNING:
Danger to life and limb while working on steering (releasing steering rod from steering gear) and on running gear (toe/ camber). The repair instructions must always be observed when carrying out repair work in the areas listed here.
- The battery must be disconnected before releasing the steering rod from the steering gear.
- When releasing the steering rod from the steering gear, make sure that the position of the steering wheel is not changed. Running gear locked or steering lock engaged.
- The steering-angle sensor must be recalibrated on the measuring platform each time the steering rod is released. The steering-angle sensor must be reinitialised whenever the power supply is interrupted (PSM indicator light comes on).
- After carrying out work on the running gear and steering, the spiral spring (airbag coil) must be centered.
NOTE:
The following conditions must be met to ensure the faultless operation of the system:
- The battery terminal clamps must be secure.
- The brake fluid level must be at the correct level.
- The system must not leak.
- Tyre size, air pressure and the condition of the tyres must be satisfactory.
NOTE:
The following points must be observed during vehicle diagnosis:
- The steering-angle sensor must be initialised whenever the power supply is interrupted (PSM indicator light on).
- The steering-angle sensor must be recalibrated after all work on the running gear.
- After troubleshooting or repairs: Erase the fault memory using the Porsche System Tester II No. 9588 and carry out a test drive.
- Read out the fault memory again after the test drive.
Communication between PSM control module and the Porsche System Tester II No. 9588
NOTE:
The following conditions must be met in order to establish communication between the PSM control module and the Porsche System Tester II No. 9588:
- Porsche System Tester II No. 9588 connected to data link connector
- Wheel speed is less than 10 km/h (6 mph)
- ABS/ASR/PSM control operation is not functioning
- PSM control module must be switched on for at least 100 msec
- The battery voltage must be greater than 6.7 V
General information on the fault memory
The fault memory of the control module can save up to ten different faults simultaneously. If all ten fault memories are occupied, the new fault overwrites the oldest fault. The fault memory content of the 'PSM control module' is maintained even in removed state.
Fault code setting conditions
Fault codes can be set in several circumstances, e.g.:
- Battery is disconnected
- Plug connections are disconnected
- Coding is faulty
- Power failure
- etc.
In these circumstances, no fault is present in the system and the fault memory must be erased.
Troubleshooting procedure
Troubleshooting can only be performed when the fault is present. In other words, specific troubleshooting can only be performed in accordance with instructions (given under Diagnosis/troubleshooting for each fault code) if the entry has the status 'present' in the fault memory.
If the fault is currently 'not present', please check the following:
- Diagnostic conditions are met
- All plug connections and ground points of the affected current path are OK
- View the fault frequency counter in the Porsche System Tester II No. 9588 using the [F8] Info key under 'Extended fault memory' and try to close alignments in any loose contacts in the system
Diagnostic conditions
NOTE:
Important: Always connect a suitable battery charging device to the vehicle electrical system battery before starting diagnosis. All unnecessary loads must also be switched off.
NOTE:
The fault can only be identified if the requirements listed under 'Diagnostic conditions' are met. For this reason, the specified procedure must be observed after a fault is repaired:
1. Erase fault memory
2. Satisfy the requirements listed under 'Diagnostic conditions'
3. Read out fault memory again
Possible causes of fault
NOTE: The 'possible causes of fault' that are responsible for creating the fault are listed here. Please note that in certain circumstances further faults can be stored in the fault memory after troubleshooting (e.g. if plugs are disconnected). These must be erased following repair work.
Diagnosis/troubleshooting
NOTE: The fault memory Info key [F8] on the Porsche System Tester II No. 9588 can be used to access the 'extended fault memory'. The following information can be displayed:
Fault type
The following fault types are possible:
- No display
- Upper limit value exceeded
- Lower limit value not reached
- Mechanical fault
- No signal/communication
- No or incorrect basic setting/adaptation
- Short circuit to B+
- Short circuit to ground
- Implausible signal
- Open circuit/short circuit to ground
- Open circuit/short circuit to B+
- Open circuit
- Electrical fault in electric circuit
- Please read out fault memory
- Faulty
- Cannot be checked now
Fault status
The following status types are possible:
- Present
- Not present
This information should be saved using the Save key [F4] and printed out.
NOTE:
Visual inspection: During troubleshooting, please check first that the affected pins on the control module plug connection are neither damaged nor corroded. The wiring and plugs of the affected components must also be checked for external damage and correct contacts. Repair damaged or corroded pins if possible, otherwise replace affected pins. Repair or replace damaged wiring.
NOTE:
Battery voltage: A battery voltage of between 11.4 and 14.5 V is required for troubleshooting. This must be checked and provided, if necessary. On the vehicle electrical system, voltage to the components and fuses (input side) must be guaranteed.
Freeze frame
Freeze frame data is standardised and secures operating conditions in the event of a fault. Freeze frames have varying priorities, this can be significant when outputting to a scan tool. They can be seen in the "extended fault memory" of the Porsche System Tester II No. 9588.
Different operating conditions can also be saved for each fault. These can provide reference points to the cause of the fault in difficult diagnoses. These can be seen in the "extended fault memory" of the Porsche System Tester II No. 9588.
Fault deletion counter
An individual deletion counter runs for every fault detected. It determines the memory storage time of the respective fault.
The deletion counter is set to 80 (presumed error), for example, the first time a fault is detected.
If an unshedded fault is recognised as healed, the fault deletion counter is set to 10, for example (fault did not occur often enough to be confirmed).
The deletion counter is set to 40, for example, each time an unshedded error is identified. It retains this value until fault healing is identified.
The deletion counter is decremented by 1 after every warm-up cycle, if it is an unshed fault or a fault that has been identified as healed (faults that have been confirmed but not identified as healed are not decremented in the deletion counter). If the deletion counter has reached the value 0, the fault is deleted from the fault memory.
Fault frequency counter
This shows how often a fault has occurred since the first time it appeared. If the value given is 1, the error has only occurred once. It may therefore be "present" or "not present". Whenever this fault occurs again (in other words, whenever the fault healing counter has been decremented in the meantime, i.e. an OK test took place) the fault frequency counter is incremented. A higher value in the fault frequency counter can therefore indicate a loose contact.