Trailer Hitch: Application and ID
Trailer hitchIntroduction
General instructions/safety instructions
NOTE:
- The trailer hitch is available as a feature that can be detached manually or one that can be adjusted electrically. The latter has additional components and functions; these are included in this description and identified as additional equipment. The automatic pivoting action of the trailer hitch can be activated and deactivated in the 'Coding' menu item in the Porsche System Tester II No. 9588.
- The trailer hitch control module monitors the electric circuits to the trailer, i.e. problems in the vehicle and trailer are recorded as faults in the trailer hitch control module. Only vehicle-related faults are described in these instructions.
- All lighting faults are saved only by the last trailer. This means that if another trailer is detected (plug inserted and then removed), all lighting faults are first erased.
- Use a suitable test cable (tool) or a trailer (which is OK) to check whether the fault is present on the vehicle or whether it originates from the trailer.
- Trailer detection' is only successful if a trailer cable, which is charged' (load connected, resistance in electric circuit) is inserted.
- When troubleshooting, the status of the fault must be observed.
- The vehicle is equipped with a 5-pin plug for the North American market; this is used to connect a 'brake booster'.
- In the event of a short circuit to B+, ensure that positive voltage is connected only when the trailer connecting cable is inserted in the vehicle wiring harness.
- Once troubleshooting has been performed in the trailer hitch control module, the fault memory of the vehicle electrical system control module must be read out and erased.
WARNING:
Risk of injury and damage when retracting or extending the trailer coupling (trailer hitch).
- Make sure that no persons, animals or obstacles are in the movement range.
- Never retract the trailer hitch if, for example, bicycle racks or other parts are fitted.
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.
NOTE:
- ParkAssist is deactivated for the rear area when the trailer connecting cable is inserted (detected trailer).
- Operation of the rear fog lights on the towing vehicle is disabled when the trailer connecting cable is inserted (detected trailer).
- The electric circuit in rear fog lights and reversing lights is not monitored for open circuits, i.e. 'open circuit' faults are not detected here. This feature was implemented because some trailers do not have these lights.
- When the trailer plug is pulled out of the socket for the first time, the alarm is triggered if the alarm system is armed. This means that the trailer is only protected against theft if it had been previously detected; vehicle was unlocked.
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.
Troubleshooting procedure
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
- Set all wiring harnesses of the affected current path to a state that corresponds to driving by pulling and shaking them
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 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). After carrying out repairs, read out the fault memory of all control modules and erase any faults that are present.
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.
1. Erase fault memory
2. Satisfy the requirements listed under 'Diagnostic conditions'
3. Read out fault memory again