Trailer Hitch: Other Porsche Cayenne I

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.

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.

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.

Fault type

The following fault types are possible

1. No display
2. Upper limit value exceeded
3. Lower limit value not reached
4. Mechanical fault
5. No signal/communication
6. No or incorrect basic setting/adaptation
7. Short circuit to B+
8. Short circuit to ground
9. Implausible signal
10. Open circuit/short circuit to ground
11. Open circuit/short circuit to B+
12. Open circuit
13. Electrical fault in electric circuit
14. Please read out fault memory
15. Faulty
16. Cannot be checked now

Fault status

The following status types are possible

1. Present
2. 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

Tools

Note. Before starting the diagnosis a suitable charging device must be connected to maintain battery capacity. Plug contacts are optimally designed to suit the plug system. Operations on pins can cause contact problems. Always use suitable measurement tools for adapter plugs and test cables.

Battery charging device

Refer to equipment instructions.

Scheme 11

Porsche System Tester II No. 9588

Refer to equipment instructions.

Scheme 12

Commercially available digital multimeter

Refer to equipment instructions.

Scheme 13

Measurement tool set No. 9684

Refer to equipment instructions.

Scheme 14

Extract and change coding

Note. After the trailer hitch control module is replaced, the coding must be customized to the vehicle equipment so that the control module knows which trailer hitch is installed and which functions are desired or necessary. Automated folding/pivoting is synonymous with comfort closing in power windows. Touching the button is sufficient to fold/pivot the trailer hitch. The 'No automatic folding/pivoting' option can be coded if there are doubts about safety. The button must be kept pressed until the trailer hitch is completely retracted or extended. With or without operating button; the operating button must be activated for the outwardly pivoting trailer hitch. This is of course not necessary for the detachable trailer hitch.

Versions or equipment features can be read out and reactivated under the 'Coding' menu item.

The following options are possible

1. USA/North America
2. RoW
3. Trailer hitch with detachable ball head
4. Trailer hitch with automatic unfolding/pivoting of the ball head - "comfort folding"
5. Without automatic folding/pivoting of the ball head - switch/button must be held

Note. When the coding is changed in the "Coding" menu item, the ignition must always be switched off afterwards and the key removed. After the ignition is switched on again, the new coding of the control module is updated and the stored faults can be erased.

Note. If the coding does not match the vehicle equipment, faults will be displayed that are not really present. The control module does not function without a valid coding entry.

Permissible combinations

Note. Ensure that only permitted combinations and existing versions are coded.

PERMITTED COMBINATIONS AND EXISTING VERSIONS

Note. Electric circuits not present on every trailer, such as fog lights or reversing lights, are not monitored for open circuit. (NAR) - North America

TRAILER HITCH FAULT OVERVIEW

Control module faulty

Note. If this trailer hitch control module fault occurs, the trailer tail light is switched on and the brake light signal is switched through.

Possible cause of fault

1. Trailer hitch control module faulty

1. Tail light bulb faulty, trailer
2. Open circuit in tail light's electrical circuit; vehicle and/or trailer
3. Short circuit to ground or B+ in line; vehicle and/or trailer

Affected pins

Trailer hitch control unit, plug A

1. Pin 4

Trailer hitch socket

1. Pin 6

1. No signal/communication (no signal from KESSY control module on CAN comfort)

Trailer hitch control module, plug B

1. Pin 7 'CAN comfort (high)'
2. Pin 8 'CAN comfort (low)'

1. No signal/communication (no signal from vehicle electrical system control module on CAN comfort)
2. Read out fault memory (from vehicle electrical system control module)

Trailer hitch control module, plug B

1. Pin 8 'CAN comfort (low)'
2. Pin 7 'CAN comfort (high)'

1. Communication via CAN comfort disrupted
2. Problem with brake light signal from brake light switch
3. Brake light relay faulty (relay carrier at left of dashboard)
4. Signal lead from brake light switch faulty (open circuit, short circuit to B+ or ground)
5. Fuse F38 and F26 (fuse carrier on the left)
6. Brake light switch faulty
7. Trailer hitch control module faulty

Trailer hitch control module, plug B

1. Pin 3

1. Battery empty or faulty
2. Lower limit value not reached (battery voltage of vehicle battery is too low)
3. Upper limit value exceeded (battery voltage of vehicle battery is too high)
4. Contact resistance at the contacts/ground points or in the wiring

Affected terminals

Terminal

1. Implausible terminal 15 signal (plug B, pin 2) or implausible data from KESSY control module via CAN comfort
2. Fuse F41, fuse carrier at right of dashboard

Note. The trailer hitch control module receives the terminal 15 signal in two ways: as an analog signal via the signal wire (plug B, pin 2) and also via the CAN comfort bus from KESSY. A cyclical check and comparison of both sets of information takes place in the trailer hitch control module (redundancy). If different comparison values are detected, a fault is stored in the fault memory.

Trailer hitch control module, plug B

1. Pin 2
2. Pin 7 'CAN comfort high'
3. Pin 8 'CAN comfort low'

1. A new, uncoded control module has been installed

1. To locales the fault, read out the fault memory for the 'gateway control module' (please read out fault memory)
2. No message from gateway on CAN comfort (no signal/communication)
3. Trailer hitch control module faulty

Trailer hitch control module, plug B

1. Pin 8 'CAN comfort (low)'
2. Pin 7 'CAN comfort (high)'

1. Short circuit between CAN lead (high) and CAN lead (low)
2. Short circuit to B+
3. Short circuit to ground
4. Fault in a control module connected to CAN comfort

Trailer hitch control module, plug B

1. Pin 8 'CAN comfort (low)'
2. Pin 7 'CAN comfort (high)'

Initialization not successful

Note. Optional feature only: The trailer hitch of the electrically adjustable trailer hitch system must become familiar with the limit stops; to do this the system must perform an initialization run! If this does not happen, the trailer hitch must be fully retracted and extended twice by holding the button.

Note. This fault can occur if the power supply fails or is interrupted during initialization The trailer hitch can only be moved by activating the button if the rear lid or rear window is open No plug or adapter may be present in the trailer socket when retracting the trailer hitch Automatic trailer hitch operation was interrupted Trailer hitch control module faulty

Trailer hitch control module, plug B

1. Pin 8 'CAN comfort (low)'
2. Pin 7 'CAN comfort (high)'

Brake actuated signal (PSM)

Note. This fault code is set if a difference is detected between the analog (brake light HIGH) and digital signal (CAN).

1. Short circuit to B+ (electrical fault in electric circuit)
2. Short circuit to ground (electrical fault in electric circuit)
3. Open circuit (electrical fault in electric circuit)

Trailer hitch control unit, connector B

1. Up to model year '05: Pin 3 'brake light' to brake light relay in relay carrier/left of dashboard
2. As of model year '05: Pin 3 'brake light' to PSM control unit

1. Open circuit in electric circuit for terminal 30; vehicle and/or trailer
2. Short circuit to ground or B+ in wiring harness; vehicle and/or trailer

Trailer hitch control module, plug A

1. Pin 16 'terminal 30'

Trailer hitch socket

1. Pin 9 'terminal 30'
2. Pin 5 'terminal 30' (North America)

Brake light, trailer

Note. This fault, together with all other lighting faults, is saved only by the last trailer. This means that if another trailer is detected (trailer in socket), all lighting faults are first erased.

1. Brake light bulb faulty, trailer
2. Open circuit in brake light's electric circuit; vehicle and/or trailer
3. Wiring has short circuit to ground or B+; vehicle and/or trailer
4. Trailer hitch control module

Trailer hitch control module, plug A

1. Pin 13

Trailer hitch socket

1. Pin 6

1. Right tail light bulb faulty, trailer
2. Open circuit in tail light's electrical circuit; vehicle and/or trailer
3. Short circuit to ground or B+ in wiring; vehicle and/or trailer

Trailer hitch control module, plug A

1. Pin 4

Trailer hitch socket

1. Pin 5
2. Pin 6 (North America)

1. Left tail light bulb faulty, trailer
2. Open circuit in left tail light's electric circuit; vehicle and/or trailer
3. Wiring has short circuit to ground or B+; vehicle and/or trailer

Trailer hitch control module, plug A

1. Pin 10

Trailer hitch socket

1. Pin 7

1. Right direction indicator light bulb faulty, trailer
2. Open circuit in right direction indicator light's electric circuit; vehicle and/or trailer
3. Short circuit to ground or B+ in wiring; vehicle and/or trailer

Trailer hitch control module, plug A

1. Pin 5

Trailer hitch socket

1. Pin 4 (Pin 4, North America)

1. Left direction indicator light bulb faulty, trailer
2. Open circuit in direction indicator light's electric circuit
3. Short circuit to ground or B+ in wiring between control module and trailer socket

Trailer hitch control module, plug A

1. Pin 7

Trailer hitch socket

1. Pin 1 (Pin 1, North America)

1. Wiring between control module and trailer socket has short circuit to ground or B+

Note. 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.

Trailer hitch control module, plug A

1. Pin 2

Trailer hitch socket

1. Pin 2 (Not North America)

1. Short circuit to ground or B+ in wiring; vehicle and/or trailer

Note. The electric circuit in rear fog lights and reversing lights is not monitored for open circuits, i.e. open circuit faults are not identified here. This was implemented in this way because some trailers do not have these lights.

Trailer hitch control module, plug A

1. Pin 3

Trailer hitch socket

1. Pin 8
2. Pin 7 (North America)

Activation of electrical brakes, trailer

Note. This fault code is used to monitor the signal leads for a retrofitted control unit of electrical trailer brakes. Faults in the trailer of their components are not detected. This fault code can only occur for NAR (North America) coding. This fault, together with all lighting faults, is saved only by the last trailer. This means that if another trailer is detected (trailer in socket), all lighting faults are first erased.

1. Retrofitted electrical brakes control unit (trailer) faulty
2. Short circuit to ground or B+ in signal lead
3. Trailer hitch control module

Trailer hitch control module, plug A

1. Pin 13

Control module plug, electrical brakes (retrofit), trailer

1. Pin 3

Left brake light, trailer

Note. This fault code can only occur for NAR (North America) coding. This fault, together with all other lighting faults, is saved only by the last trailer. This means that if another trailer is detected (trailer in socket), all lighting faults are first erased.

1. Left brake light/direction indicator light bulb faulty, trailer
2. Open circuit in left brake light/direction indicator light electrical circuit; vehicle and/or trailer
3. Short circuit to ground or B+ in wiring; vehicle and/or trailer
4. Trailer hitch control module

Trailer hitch control module, plug A

1. Pin 7

Trailer hitch socket

1. Pin 1

Right brake light, trailer

Note. This fault code can only occur for NAR (North America) coding. This fault, together with all other lighting faults, is saved only by the last trailer. This means that if another trailer is detected (trailer in socket), all lighting faults are first erased.

1. Right brake light/direction indicator light bulb faulty, trailer
2. Open circuit in right brake light/direction indicator light electrical circuit; vehicle and/or trailer
3. Short circuit to ground or B+ in wiring; vehicle and/or trailer
4. Trailer hitch control module

Trailer hitch control module, plug A

1. Pin 5

Trailer hitch socket

1. Pin 4

1. Communication via CAN comfort disrupted
2. No initialization performed (learn limit stops by driving off with button pressed)
3. Open circuit or short circuit in positioning motor's signal and supply leads
4. Mechanical fault in positioning motor

Trailer hitch control module, plug A

1. Pin 1, pin 8, pin 11, pin 12, pin 14

Plug for pivoting motor

1. Pin 1, pin 2, pin 3, pin 4, pin 5