Transfer Box Porsche Cayenne S I

Diagnosis software number: VG 0101

Cayenne model year 2003

General instructions/safety instructions

Note. The following conditions must be met in order to establish communication between the transfer box control module and the Porsche System Tester II No. 9588

1. Porsche System Tester II No. 9588 connected to data link connector
2. The battery voltage must be greater than 6.5 V

General information on the fault memory

The fault memory of the control module can save up to (X) different faults simultaneously. If all (X) fault memories are full, the new fault overwrites the oldest fault. The fault memory content of the 'transfer box control module' is maintained even in removed state.

Fault code setting conditions

Fault codes can be set in various circumstances, e.g.

1. battery disconnected
2. plug connections disconnected
3. faulty coding
4. power failure
5. 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

1. Diagnostic conditions are met
2. All plug connections and ground points of the affected current path are OK
3. View the fault frequency counter in the Porsche System Tester II No. 9588 using the fault memory Info key [F8] under 'Extended fault memory' and try to reach conclusions about eliminating any loose contacts in the system.

Diagnostic conditions

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.

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

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.

Note. Visual inspection: During troubleshooting, please check first that the affected pins on the control module plug connection are neither damaged nor corroded. The wires 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 wires.

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. Voltages to components or fuses (input side) must be guaranteed on the vehicle electrical system.

Freeze frame (frozen fault boundary conditions)

Freeze frame data is standardised and records operating conditions in the event of a fault. Freeze frames have different priorities, which can be important when output to a Scan Tool. These can be viewed in the "extended fault memory" of the Porsche System Tester II No. 9588.

Furthermore, various operating conditions can be stored for each fault. These can provide reference points for determining the cause of a fault in the case of difficult diagnoses. These can be viewed 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 storage duration of the related fault.

When a fault is first detected, the deletion counter is set to 80, for example (suspected fault).

If an unshedded fault is detected as having been remedied, the deletion counter is set to 10, for example (fault did not occur often enough to be confirmed).

Whenever a shedded fault is detected, the deletion counter is set to 40, for example. This value is retained until the fault is detected as having been remedied.

The deletion counter is decremented by 1 after every warm-up cycle if the fault in question is an unshedded fault or is detected as having been remedied (faults that are confirmed, but are not detected as having been remedied are not decremented in the deletion counter). If the deletion counter reaches the value 0, the fault is deleted from the memory.

Fault frequency counter

This counter shows how often a fault has recurred following its first occurrence. If the frequency value is 1, the fault has only occurred once. It can now be either "present" or "not present". The fault frequency counter is incremented whenever this fault recurs (the fault healing counter was decremented in the meantime, i.e. a check was performed and found to be OK). A higher value in the fault frequency counter can therefore indicate a loose contact.

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.

Scheme 1

Scheme 2

Scheme 3

Scheme 4

Scheme 5

Component arrangement 'Item 6' Transfer box with components

1 - Transfer box servo motor

A - Servo motor plug connection (power and ground supply for brake and motor)

B - Sensor plug connection

Scheme 6

Component arrangement 'Item 10' Selector switch (running gear control module)

1 - Selector switch housing

2 - Selector switch housing lower part

3 - Symbols 'Level control LED'

4 - Slider 'Manual set level'

5 - Switch 'PASM running gear tuning'

6 - Slider 'Manual set longitudinal lock/transverse lock/gear reduction'

7 - Symbols 'Longitudinal lock/transverse lock/gear reduction LED'

Scheme 7

Scheme 8

CONNECTOR TERMINALS REFERENCE CHART

Gear selection switch connector assignment (running gear control module), '16-pin'

A - Plug connection for 'gear selection switch (running gear control module)' (at underside of housing)

Scheme 9

CONNECTOR TERMINALS REFERENCE CHART

Integrated functions

The transfer box control module includes the functions listed below

1. Computer identification
2. Computer configuration with ignition ON
3. Checking the fault memory for fault entries, even in diagnostic mode
4. Deleting the fault memory
5. Reading measured values from switches and sensors

Supported functions

1. Diagnosis software number
2. Drive link test with active fault checking

Basic setting

1. Adaptation/Resetting adaptation values
2. Read memory
3. Write memory
4. Update programme
5. Flash programme (end of volume)
6. Protected against unauthorised access

Commissioning

When the ignition 'terminal 15' is switched on, an internal function test (initialisation phase) is performed in the transfer box control module. When the internal function test is completed successfully, all functions integrated into the transfer box control module are released.

Operating mode

The transfer box control module is in operating mode once the ignition is switched on and the internal function test is completed successfully. Within the defined limits for power supply and temperature, all incoming signals are processed by the integrated software and the appropriate monitoring and control processes are performed.

Data transfer

The transfer box control module sends and receives data/information via the following 'CAN data bus'

1. CAN drive (C)
2. Gateway (in instrument cluster)

Fault memory

Faults that occur during operation are stored in a non-volatile memory (e.g. EEPROM). The faults remain in the memory even if terminal 15 and terminal 30 are not live. The fault memory is designed in such a way that the occurring faults, data source, fault type and fault deletion counter can be saved. The transfer box control module sends messages and checks the CAN drive cyclically for messages from other control modules. If no messages are received for a certain time period, a fault is stored in the fault memory.

Adaptation

Work to be carried out after replacing a control module

1. Delete the adaptation values using the Porsche System Tester II No. 9588

Coding

Note. The transfer box control module does not have to be coded!

FAULT REFERENCE CHART

1. Ignition on
2. Internal transfer box control module function test

1. 'Below lower limit', battery discharged or faulty
2. 'Lower limit value not reached', fuse faulty
3. 'Below lower limit', line short circuit to ground or open circuit
4. 'Below lower limit', alternator faulty
5. 'Below lower limit', transfer box control unit faulty
6. 'Above upper limit', alternator faulty
7. 'Above upper limit', transfer box control unit faulty

Affected pins

Transfer box control module plug

1. Pin 46 'terminal 30', from fuse carrier at right of dashboard 'fuse 57'
2. Pin 47 'ground', from ground pin 'MB26'

Note. Visual inspection: In the next troubleshooting section, please check first that the affected 'pin' of the transfer box control unit plug connection and the 'pin' of the plug connections are neither damaged nor corroded. Remove any soiling or corrosion/oxidation. Replace damaged parts/wires.

Note. Control unit replacement: Before replacing the 'transfer box control unit', the ground connections, power supply and plug connections on the control unit must be checked as OK. After the test drive, read out the fault memory with the 9588 Porsche System Tester II again. Additional causes of faults that could damage the 'transfer box control unit' should be detected and remedied.

Before carrying out the work instruction, check fuse '57', voltage supply terminal 30 for the transfer box control unit, in the fuse carrier to the right of the dashboard and replace if necessary. After replacing the fuse, determine and remedy the cause of the fault in accordance with the work instruction below!

DIAGNOSIS TROUBLESHOOTING PROCEDURE

1. Ignition on
2. Internal control module function test not completed successfully

1. When the ignition is switched on, an internal function test is performed in the transfer box control module, but this was not completed successfully (implausible signal)

Note. The internal function test must be completed successfully before the functions in the transfer box control module can be released.

Transfer box control module plug

Diagnosis/troubleshooting VG 0101

Note. Before replacing the control module, the ground connections, power supply and plug connections on the control module must be checked. After the test drive, read out the fault memory again with the Porsche System Tester II No. 9588. Additional causes of faults that could damage the transfer box control module should be detected and remedied.

DIAGNOSIS TROUBLESHOOTING PROCEDURE

1. Ignition on
2. Internal control module function test

1. No message from steering-angle sensor (no signal/communication)

Transfer box control module plug

1. Pin 11 'CAN drive (low)'
2. Pin 42 'CAN drive (high)'

Note. If there is no incoming signal/message via the CAN drive using several control modules, the CAN drive must be checked for open or short circuits. Refer to ' CHECKING INSTRUCTIONS/CAN DATA BUS '.

DIAGNOSIS TROUBLESHOOTING PROCEDURE

1. Ignition on
2. Internal transfer box control module function test

Possible cause of fault

Communication problem with all control modules via CAN drive.

1. CAN drive is faulty
2. No signal/communication

Transfer box control module plug

1. Pin 11 'CAN drive (low)'
2. Pin 42 'CAN drive (high)'

Note. If there is no incoming signal/message via the CAN drive using several control modules, the CAN drive must be checked for open or short circuits. Refer to ' CHECKING INSTRUCTIONS/CAN DATA BUS '.

DIAGNOSIS TROUBLESHOOTING PROCEDURE

1. Ignition on
2. Internal control module function test

Communication problem with all control modules via CAN drive.

1. To localise the fault, read out the fault memory for the 'DME control module' (Please read out fault memory)
2. No message from DME control module on CAN drive (no signal/ communication)

Transfer box control module plug

1. Pin 11 'CAN drive (low)'
2. Pin 42 'CAN drive (high)'

Note. If there is no incoming signal/message via the CAN drive using several control modules, the CAN drive must be checked for open or short circuits. Refer to ' CHECKING INSTRUCTIONS/CAN DATA BUS '.

DIAGNOSIS TROUBLESHOOTING PROCEDURE

1. Ignition on
2. Internal control module function test

1. To localise the fault, read out the 'Tiptronic control module' fault memory (Please read out fault memory)
2. No message from Tiptronic control module on CAN drive (no signal/communication)

Transfer box control module plug

1. Pin 11 'CAN drive (low)'
2. Pin 42 'CAN drive (high)'

Note. If there is no incoming signal/message via the CAN drive using several control modules, the CAN drive must be checked for open or short circuits. Refer to ' CHECKING INSTRUCTIONS/CAN DATA BUS '.

DIAGNOSIS TROUBLESHOOTING PROCEDURE

1. Ignition on
2. Internal control module function test
3. Vehicle speed greater than 0 km/h

1. To localise the fault, read out the fault memory for the 'PSM control module' (Please read out fault memory)
2. No message from PSM control module on CAN drive (no signal/ communication)

Transfer box control module plug

1. Pin 11 'CAN drive (low)'
2. Pin 42 'CAN drive (high)'

Note. If there is no incoming signal/message via the CAN drive using several control modules, the CAN drive must be checked for open or short circuits. Refer to ' CHECKING INSTRUCTIONS/CAN DATA BUS '.

DIAGNOSIS TROUBLESHOOTING PROCEDURE

1. Ignition on
2. Internal control module function test

1. Signal from instrument cluster does not correspond to expected signal (please read out fault memory).
2. Signal from instrument cluster does not appear on CAN drive (no signal/communication).

Transfer box control module plug

1. Pin 11 'CAN drive (low)'
2. Pin 42 'CAN drive (high)'

Note. If there is no incoming signal/message via the CAN drive using several control modules, the CAN drive must be checked for open or short circuits. Refer to ' CHECKING INSTRUCTIONS/CAN DATA BUS '.

DIAGNOSIS TROUBLESHOOTING PROCEDURE

1. Ignition on
2. Internal control module function test

1. To localise the fault, read out the fault memory for the 'gateway (in instrument cluster)' (Please read out fault memory)
2. No message from CAN comfort (the messages are transferred to the CAN drive via the 'gateway' interface in the instrument cluster) on CAN drive (no signal/communication)

Transfer box control module plug

1. Pin 11 'CAN drive (low)'
2. Pin 42 'CAN drive (high)'

DIAGNOSIS TROUBLESHOOTING PROCEDURE

1. Ignition on
2. Internal transfer box control module function test

1. Transfer box control module faulty

Note. Before replacing the control module, the ground connections, power supply and plug connections on the control module must be checked. After the test drive, read out the fault memory again with the Porsche System Tester II No. 9588. Additional causes of faults that could damage the transfer box control module should be detected and remedied.

DIAGNOSIS TROUBLESHOOTING PROCEDURE

1. Ignition on
2. Internal transfer box control module function test

1. Transfer box control module faulty

Note. Before replacing the control module, the ground connections, power supply and plug connections on the control module must be checked. After the test drive, read out the fault memory again with the Porsche System Tester II No. 9588. Additional causes of faults that could damage the transfer box control module should be detected and remedied.

DIAGNOSIS TROUBLESHOOTING PROCEDURE

1. Ignition on
2. Internal transfer box control module function test

1. Transfer box control module faulty

Note. Before replacing the control module, the ground connections, power supply and plug connections on the control module must be checked. After the test drive, read out the fault memory again with the Porsche System Tester II No. 9588. Additional causes of faults that could damage the transfer box control module should be detected and remedied.

DIAGNOSIS TROUBLESHOOTING PROCEDURE

Control unit malfunction

This fault causes the power/voltage supply to the servo motor 'A/B', brakes 'A/B', sensors and CAN communication to switch off.

Note. The internal function test must be completed successfully before the functions stored in the transfer box control unit can be activated.

1. Ignition on
2. Internal transfer box control unit function test

1. 'Implausible signal': fault detected in computer during internal function test in transfer box control unit.

Transfer box control unit plug

1. Pin '-'

Note. Before replacing the control unit, the ground connections, power supply and plug connections on the control unit must be checked. After the test drive, read out the fault memory with the Porsche System Tester II No. 9588 again. Additional causes of faults that could damage the transfer box control unit should be detected and remedied.

DIAGNOSIS TROUBLESHOOTING PROCEDURE

This fault causes the power/voltage supply to the servo motor 'A/B', brakes 'A/B', sensors and CAN communication to switch off.

Note. The internal function test must be completed successfully before the functions stored in the transfer box control unit can be activated.

1. Ignition on
2. Internal transfer box control unit function test

1. 'Implausible signal': fault detected in computer during internal function test in transfer box control unit.

Transfer box control unit plug

1. Pin '-'

Note. Before replacing the control unit, the ground connections, power supply and plug connections on the control unit must be checked. After the test drive, read out the fault memory with the Porsche System Tester II No. 9588 again. Additional causes of faults that could damage the transfer box control unit should be detected and remedied.

DIAGNOSIS TROUBLESHOOTING PROCEDURE

1. Ignition on
2. Internal function test on transfer box control unit

1. 'Short circuit to B+' between 'PWM (Pulse Width Modulation) switch' and 'selector switch (in running gear control module)'
2. 'Short circuit to ground' between 'PWM (Pulse Width Modulation) switch' and 'selector switch (in running gear control module)'
3. 'Open circuit' between 'PWM (Pulse Width Modulation) switch' and 'selector switch (in running gear control module)'

Transfer box control unit connector

1. Pin 7 'PWM (Pulse Width Modulation) switch' to 'pin 4' 'selector switch (in running gear control module)'

Note. Visual inspection: In the next troubleshooting section, please check first that the affected 'pins' on the transfer box control unit plug connection and the 'pins' on the plug connections on the 'selector switch (in running gear control module)' are neither damaged nor corroded. Remove any soiling or corrosion/oxidation. Replace damaged parts/wiring.

Note. Control unit replacement: before replacing the 'transfer box control unit', the ground connections, power supply and plug connections on the control unit must be checked and found to be OK. After test-driving the vehicle, read out the fault memory again using the 9718 PIWIS tester. Additional causes of faults that could damage the 'transfer box control unit' should be detected and remedied.

DIAGNOSIS TROUBLESHOOTING PROCEDURE

Note. This fault code relates to the signal of potentiometer '2' (sensor 2) which, together with potentiometer '1' (sensor 1) and the temperature sensor, is integrated as a unit in the servo motor.

1. Ignition on
2. Internal transfer box control module function test

1. 'Short circuit to B+': signal line of potentiometer '2' (sensor 2) short circuit to B+(12 V)
2. 'Short circuit to B+': transfer box control unit faulty
3. 'Open circuit/short circuit to ground': signal line of potentiometer '2' (sensor 2) open circuit or short circuit to ground
4. 'Short circuit to ground': potentiometer faulty
5. 'Open circuit/short circuit to ground': transfer box control unit faulty

Transfer box control module plug

1. Pin 31 'input signal to potentiometer 2 (sensor 2)', from pin B8 of 'servo motor sensor plug'

Note. Visual inspection: In the next troubleshooting section, please check first that the affected 'pins' of the transfer box control unit plug connection and the 'pins' of the plug connections on the servo motor are neither damaged nor corroded. Remove any soiling or corrosion/oxidation. Replace damaged parts/wires.

Note. Control unit replacement: Before replacing the 'transfer box control unit', the ground connections, power supply and plug connections on the control unit must be checked as OK. Please observe the coding of the control module. After the test drive, read out the fault memory with the 9588 Porsche System Tester II again. Additional causes of faults that could damage the 'transfer box control unit' should be detected and remedied.

Troubleshooting fault type: 'short circuit to B+'

DIAGNOSIS TROUBLESHOOTING PROCEDURE

Troubleshooting fault type: 'Open circuit/short circuit to ground'

DIAGNOSIS TROUBLESHOOTING PROCEDURE

Voltage supply to sensors

Note. This fault code relates to the voltage supply to sensors: potentiometer '1' (sensor 1), potentiometer '2' (sensor 2) and the servo motor temperature sensor, which are integrated as a unit in the servo motor.

1. Ignition on
2. Internal transfer box control unit function test

1. 'Above upper limit': voltage supply line (5 V) short circuit to B+ (12 V)
2. 'Above upper limit': transfer box control unit faulty
3. 'Below lower limit': voltage supply line (5 V) short circuit to ground
4. 'Below lower limit': transfer box control unit faulty

Transfer box control unit plug

1. Pin 1 'potentiometer 1 (sensor 1) 5 V to pin B4 of 'servo motor sensor plug'
2. Pin 18 'potentiometer 2 (sensor 2) 5 V to pin B10 of 'servo motor sensor plug'
3. Pin 29 'voltage supply (5 V) for servo motor temperature sensor' to pin B6 of 'servo motor sensor plug'

Note. Visual inspection: In the next troubleshooting section, please check first that the affected 'pins' of the transfer box control unit plug connection and the 'pins' of the plug connections on the servo motor are neither damaged nor corroded. Remove any soiling or corrosion/oxidation. Replace damaged parts/wires.

Note. Control unit replacement: Before replacing the 'transfer box control unit', the ground connections, power supply and plug connections on the control unit must be checked as OK. Please observe the coding of the control unit. After the test drive, read out the fault memory again with the Porsche System Tester II No. 9588. Additional causes of faults that could damage the 'transfer box control unit' should be detected and remedied.

DIAGNOSIS TROUBLESHOOTING PROCEDURE

Note. This fault code relates to the signal of potentiometer '2' (sensor 2) and potentiometer '1' (sensor 1) which, together with the temperature sensor, are integrated as a unit in the servo motor.

1. Ignition on
2. Internal transfer box control module function test

1. 'Short circuit to B+': signal line of potentiometer '1/2' (sensor 1/ 2) short circuit to B+(12 V)
2. 'Short circuit to B+': transfer box control unit faulty
3. 'Open circuit/short circuit to ground': signal line of potentiometer '1/2' (sensor 1/2) open circuit or short circuit to ground
4. 'Short circuit to ground': potentiometer faulty
5. 'Open circuit/short circuit to ground': transfer box control unit faulty
6. 'Implausible signal': potentiometer faulty

Transfer box control module plug

1. Pin 12 'input signal to potentiometer 1 (sensor 1)', from pin B5 of 'servo motor sensor plug'
2. Pin 31 'input signal to potentiometer 2 (sensor 2)', from pin B8 of 'servo motor sensor plug'

Note. Visual inspection: In the next troubleshooting section, please check first that the affected 'pins' of the transfer box control unit plug connection and the 'pins' of the plug connections on the servo motor are neither damaged nor corroded. Remove any soiling or corrosion/oxidation. Replace damaged parts/wires.

Note. Control unit replacement: Before replacing the 'transfer box control unit', the ground connections, power supply and plug connections on the control unit must be checked as OK. Please observe the coding of the control module. After the test drive, read out the fault memory with the 9588 Porsche System Tester II again. Additional causes of faults that could damage the 'transfer box control unit' should be detected and remedied.

DIAGNOSIS TROUBLESHOOTING PROCEDURE

DIAGNOSIS TROUBLESHOOTING PROCEDURE

Troubleshooting for fault type: 'implausible signal'

DIAGNOSIS TROUBLESHOOTING PROCEDURE

1. Ignition on
2. Internal transfer box control module function test
3. Engine running
4. Selector lever position 'P'
5. Engage longitudinal lock/gear reduction

1. 'Short circuit to B+': short circuit in wiring harness (servo motor runs continuously)
2. 'Short circuit to B+': control unit faulty (servo motor runs continuously)
3. 'Short circuit to ground': short circuit in wiring harness (servo motor does not function)
4. 'Short circuit to ground': short in servo motor winding or short circuit in servo motor leads (servo motor does not function)
5. 'Short circuit to ground': control unit faulty (servo motor does not function)

Transfer box control module plug

1. Pin 15 'servo motor (A)', to pin A1 of 'servo motor plug A'
2. Pin 16 'servo motor (B)', to pin A4 of 'servo motor plug B'

Note. Visual inspection: In the next troubleshooting section, please check first that the affected 'pins' of the transfer box control unit plug connection and the 'pins' of the plug connections on the servo motor are neither damaged nor corroded. Remove any soiling or corrosion/oxidation. Replace damaged parts/wires.

Note. Control unit replacement: Before replacing the 'transfer box control unit', the ground connections, power supply and plug connections on the control unit must be checked as OK. Please observe the coding of the control module. After the test drive, read out the fault memory with the 9588 Porsche System Tester II again. Additional causes of faults that could damage the 'transfer box control unit' should be detected and remedied.

DIAGNOSIS TROUBLESHOOTING PROCEDURE

Troubleshooting fault type: 'short circuit to ground'

DIAGNOSIS TROUBLESHOOTING PROCEDURE

1. Ignition on
2. Internal transfer box control module function test
3. Engine running
4. Selector lever position 'P'
5. Engage longitudinal lock/gear reduction

1. 'Short circuit to B+': short circuit in wiring harness (servo motor does not function)
2. 'Short circuit to B+': control unit faulty (servo motor does not function)
3. 'Short circuit to ground': short circuit in wiring harness (servo motor runs continuously)
4. 'Short circuit to ground': short in servo motor winding or short circuit in servo motor leads (servo motor runs continuously)
5. 'Short circuit to ground': control unit faulty (servo motor runs continuously)

Transfer box control module plug

1. Pin 15 'servo motor (A)', to pin A1 of 'servo motor plug A'
2. Pin 16 'servo motor (B)', to pin A4 of 'servo motor plug B'

Note. Visual inspection: In the next troubleshooting section, please check first that the affected 'pins' of the transfer box control unit plug connection and the 'pins' of the plug connections on the servo motor are neither damaged nor corroded. Remove any soiling or corrosion/oxidation. Replace damaged parts/wires.

Note. Control unit replacement: Before replacing the 'transfer box control unit', the ground connections, power supply and plug connections on the control unit must be checked as OK. Please observe the coding of the control module. After the test drive, read out the fault memory with the 9588 Porsche System Tester II again. Additional causes of faults that could damage the 'transfer box control unit' should be detected and remedied.

DIAGNOSIS TROUBLESHOOTING PROCEDURE

DIAGNOSIS TROUBLESHOOTING PROCEDURE

1. Ignition on
2. Internal transfer box control unit function test
3. Engine running
4. Selector lever position 'P'
5. Engage longitudinal lock/gear reduction

1. 'Open circuit': open circuit between leads (servo motor does not function)
2. 'Open circuit': control unit faulty (servo motor does not function)
3. 'Open circuit': open circuit in servo motor winding (servo motor does not function)

Transfer box control unit plug

1. Pin 15 'servo motor (A)', to pin A1 of 'servo motor plug A'
2. Pin 16 'servo motor (B)', to pin A4 of 'servo motor plug B'

Note. Visual inspection: In the next troubleshooting section, please check first that the affected 'pins' of the transfer box control unit plug connection and the 'pins' of the plug connections on the servo motor are neither damaged nor corroded. Remove any soiling or corrosion/oxidation. Replace damaged parts/wires.

Note. Control unit replacement: Before replacing the 'transfer box control unit', the ground connections, power supply and plug connections on the control unit must be checked as OK. Please observe the coding of the control unit. After the test drive, read out the fault memory again with the Porsche System Tester II No. 9588. Additional causes of faults that could damage the 'transfer box control unit' should be detected and remedied.

DIAGNOSIS TROUBLESHOOTING PROCEDURE

1. Ignition on
2. Internal transfer box control module function test

If short circuit to B+

Engage gear reduction.

If short circuit to ground

Do not engage gear reduction.

'Gear reduction LED' is activated by transfer box control unit on the ground side.

1. 'Short circuit to B+': gear reduction LED does not light
2. 'Short circuit to ground': gear reduction LED permanently lit

Transfer box control module plug

1. Pin 4 'gear reduction LED', to gear reduction LED (in running gear control module) 'pin 13'

Note. Visual inspection: In the next troubleshooting section, please check first that the affected 'pins' of the transfer box control unit plug connection and the 'pins' of the plug connections on the servo motor are neither damaged nor corroded. Remove any soiling or corrosion/oxidation. Replace damaged parts/wires.

Note. Control unit replacement: Before replacing the 'transfer box control unit', the ground connections, power supply and plug connections on the control unit must be checked as OK. After the test drive, read out the fault memory with the 9588 Porsche System Tester II again. Additional causes of faults that could damage the 'transfer box control unit' should be detected and remedied.

DIAGNOSIS TROUBLESHOOTING PROCEDURE

1. Ignition on
2. Internal transfer box control module function test

If short circuit to B+

Engage longitudinal lock.

If short circuit to ground

Do not engage longitudinal lock.

'Longitudinal lock LED' is activated by transfer box control unit on the ground side.

1. 'Short circuit to B+': longitudinal lock LED does not light
2. 'Short circuit to ground': longitudinal lock LED permanently lit

Transfer box control module plug

1. Pin 20 'longitudinal lock LED', to longitudinal lock LED (in running gear control module) 'pin 14'

Note. Visual inspection: In the next troubleshooting section, please check first that the affected 'pins' of the transfer box control unit plug connection and the 'pins' of the plug connections on the servo motor are neither damaged nor corroded. Remove any soiling or corrosion/oxidation. Replace damaged parts/wires.

Note. Control unit replacement: Before replacing the 'transfer box control unit', the ground connections, power supply and plug connections on the control unit must be checked as OK. After the test drive, read out the fault memory with the 9588 Porsche System Tester II again. Additional causes of faults that could damage the 'transfer box control unit' should be detected and remedied.

DIAGNOSIS TROUBLESHOOTING PROCEDURE

1. Ignition on
2. Internal transfer box control module function test

If short circuit to B+

Engage transverse lock.

If short circuit to ground

Do not engage transverse lock.

'Transverse lock LED' is activated by transfer box control unit on the ground side.

1. 'Short circuit to B+': transverse lock LED does not light
2. 'Short circuit to ground': transverse lock LED permanently lit

Transfer box control module plug

1. Pin 35 'transverse lock LED', to transverse lock LED (in running gear control module) 'pin 6'

Note. Visual inspection: In the next troubleshooting section, please check first that the affected 'pins' of the transfer box control unit plug connection and the 'pins' of the plug connections on the servo motor are neither damaged nor corroded. Remove any soiling or corrosion/oxidation. Replace damaged parts/wires.

Note. Control unit replacement: Before replacing the 'transfer box control unit', the ground connections, power supply and plug connections on the control unit must be checked as OK. After the test drive, read out the fault memory with the 9588 Porsche System Tester II again. Additional causes of faults that could damage the 'transfer box control unit' should be detected and remedied.

DIAGNOSIS TROUBLESHOOTING PROCEDURE

Note. After successful read out the fault memory must be erased and after satisfying the diagnostic conditions below must be read out again!

1. Ignition on
2. Internal transfer box control unit function test
3. Vehicle stationary
4. Engine running
5. Brake actuated
6. Selector lever position 'N'
7. Via the left rocker switch on the 'selector switch (running gear control module)', alternately select the functions 'off-road driving program' and 'on-road driving program' (see Driver's Manual)

1. 'Mechanical fault': mechanical wear in transfer box

Transfer box control unit plug

1. Pin '-'

DIAGNOSIS TROUBLESHOOTING PROCEDURE

1. Ignition on
2. Internal control module function test

1. Incorrect software version (no display)

Tiptronic control module plug

DIAGNOSIS TROUBLESHOOTING PROCEDURE

Control unit switched off due to excess temperature

Note. This fault may be stored after extreme oft-road driving. This does not necessarily mean a fault is present!

1. Ignition on
2. Internal transfer box control unit function test
3. Engine running
4. Selector lever position 'P'
5. Engage longitudinal lock

1. 'Above upper limit': heavy demand on servo motor (mechanical stress)
2. 'Above upper limit': mechanical wear of servo motor
3. 'Above upper limit': transfer box control unit faulty

Transfer box control unit plug

1. Pin

Note. Visual inspection: In the next troubleshooting section, please check first that the affected 'pins' of the transfer box control unit plug connection and the 'pins' of the plug connections on the servo motor are neither damaged nor corroded. Remove any soiling or corrosion/oxidation. Replace damaged parts/wires.

Note. Control unit replacement: Before replacing the 'transfer box control unit', the ground connections, power supply and plug connections on the control unit must be checked as OK. Please observe the coding of the control unit. After the test drive, read out the fault memory again with the Porsche System Tester II No. 9588. Additional causes of faults that could damage the 'transfer box control unit' should be detected and remedied.

DIAGNOSIS TROUBLESHOOTING PROCEDURE

1. Ignition on
2. Internal control module function test

Communication problem with all control modules via CAN drive.

1. No message via CAN drive (no signal/communication)
2. Internal fault in transfer box control module (faulty)

Transfer box control module plug

1. Pin 11 'CAN drive (low)'
2. Pin 42 'CAN drive (high)'

Note. If there is no incoming signal/message via the CAN drive using several control modules, the CAN drive must be checked for open or short circuits. Refer to ' CHECKING INSTRUCTIONS/CAN DATA BUS '.

DIAGNOSIS TROUBLESHOOTING PROCEDURE

1. Ignition on
2. Internal control module function test

1. To localise the fault, read out the fault memory for the 'transverse lock control module' (Please read out fault memory)
2. No message from transverse lock control module on CAN drive (no signal/communication)

Transfer box control module plug

1. Pin 11 'CAN drive (low)'
2. Pin 42 'CAN drive (high)'

Note. If there is no incoming signal/message via the CAN drive using several control modules, the CAN drive must be checked for open or short circuits. Refer to ' CHECKING INSTRUCTIONS/CAN DATA BUS '.

DIAGNOSIS TROUBLESHOOTING PROCEDURE

1. Ignition on
2. Internal transfer box control module function test
3. Engine running
4. Selector lever position 'P'
5. Engage longitudinal lock/gear reduction

1. 'Short circuit to B+': short circuit in wiring harness (brake for servo motor continuously activated)
2. 'Short circuit to B+': control unit faulty (brake for servo motor continuously activated)
3. 'Short circuit to ground': short circuit in wiring harness (brake for servo motor does not activate)
4. 'Short circuit to ground': short in servo motor winding or short circuit in servo motor leads (brake for servo motor does not activate)
5. 'Short circuit to ground': control unit faulty (brake for servo motor does not activate)

Transfer box control module plug

1. Pin 21 'supply voltage to brake for servo motor (A)', to pin A2 of 'servo motor plug A'

Note. Visual inspection: In the next troubleshooting section, please check first that the affected 'pins' of the transfer box control unit plug connection and the 'pins' of the plug connections on the servo motor are neither damaged nor corroded. Remove any soiling or corrosion/oxidation. Replace damaged parts/wires.

Note. Control unit replacement: Before replacing the 'transfer box control unit', the ground connections, power supply and plug connections on the control unit must be checked as OK. Please observe the coding of the control module. After the test drive, read out the fault memory with the 9588 Porsche System Tester II again. Additional causes of faults that could damage the 'transfer box control unit' should be detected and remedied.

DIAGNOSIS TROUBLESHOOTING PROCEDURE

DIAGNOSIS TROUBLESHOOTING PROCEDURE

1. Ignition on
2. Internal transfer box control unit function test
3. Engine running
4. Selector lever position 'P'
5. Engage longitudinal lock/gear reduction

1. 'Short circuit to B+': short circuit in wiring harness (brake for servo motor does not activate)
2. 'Short circuit to B+': short circuit in wiring harness (brake for servo motor does not activate)
3. 'Short circuit to B+': control unit faulty (brake for servo motor does not activate)

Transfer box control unit plug

1. Pin 36 'ground supply to brake for servo motor (B)', to pin A3 of 'servo motor plug A'

Note. Visual inspection: In the next troubleshooting section, please check first that the affected 'pins' of the transfer box control unit plug connection and the 'pins' of the plug connections on the servo motor are neither damaged nor corroded. Remove any soiling or corrosion/oxidation. Replace damaged parts/wires.

Note. Control unit replacement: Before replacing the 'transfer box control unit', the ground connections, power supply and plug connections on the control unit must be checked as OK. Please observe the coding of the control unit. After the test drive, read out the fault memory again with the Porsche System Tester II No. 9588. Additional causes of faults that could damage the 'transfer box control unit' should be detected and remedied.

DIAGNOSIS TROUBLESHOOTING PROCEDURE

Servo motor temperature sensor

Note. The servo motor temperature sensor is integrated with potentiometer '1' (sensor 1) and potentiometer '2' (sensor 2) as a unit in the servo motor.

1. Ignition on
2. Internal transfer box control module function test

1. 'Open circuit/short circuit to B+': short circuit to B+ (12 V) in the voltage supply (5 V)/ground supply wiring
2. 'Open circuit/short circuit to B+': open circuit in the voltage supply (5 V)/ground supply wiring
3. 'Short circuit to ground': short circuit to ground in the voltage supply (5 V)/ground supply wiring
4. 'Above upper limit': short circuit to B+ (12 V) in the voltage supply (5 V) wiring
5. 'Above upper limit', servo motor temperature sensor faulty

Transfer box control module plug

1. Pin 29 'voltage supply (5 V) for servo motor temperature sensor' to pin B6 of 'servo motor sensor plug'
2. Pin 44 'ground for servo motor temperature sensor' to pin B7 of 'servo motor sensor plug'

Note. Visual inspection: In the next troubleshooting section, please check first that the affected 'pins' of the transfer box control unit plug connection and the 'pins' of the plug connections on the servo motor are neither damaged nor corroded. Remove any soiling or corrosion/oxidation. Replace damaged parts/wires.

Note. Control unit replacement: Before replacing the 'transfer box control unit', the ground connections, power supply and plug connections on the control unit must be checked as OK. Please observe the coding of the control module. After the test drive, read out the fault memory with the 9588 Porsche System Tester II again. Additional causes of faults that could damage the 'transfer box control unit' should be detected and remedied.

Troubleshooting fault type: 'Open circuit/short circuit to B+' and 'above upper limit'

DIAGNOSIS TROUBLESHOOTING PROCEDURE

DIAGNOSIS TROUBLESHOOTING PROCEDURE

Voltage supply for servo motor temperature sensor

Note. The servo motor temperature sensor is integrated with potentiometer '1' (sensor 1) and potentiometer '2' (sensor 2) as a unit in the servo motor.

1. Ignition on
2. Internal transfer box control module function test

1. 'Short circuit to B+': voltage supply line (5 V) short circuit to B+ (12 V)
2. 'Short circuit to B+': transfer box control unit faulty
3. 'Short circuit to ground': voltage supply line (5 V) short circuit to ground
4. 'Short circuit to ground': transfer box control unit faulty

Transfer box control module plug

1. Pin 29 'voltage supply (5 V) for servo motor temperature sensor' to pin B6 of 'servo motor sensor plug'

Note. Visual inspection: In the next troubleshooting section, please check first that the affected 'pins' of the transfer box control unit plug connection and the 'pins' of the plug connections on the servo motor are neither damaged nor corroded. Remove any soiling or corrosion/oxidation. Replace damaged parts/wires.

Note. Control unit replacement: Before replacing the 'transfer box control unit', the ground connections, power supply and plug connections on the control unit must be checked as OK. Please observe the coding of the control module. After the test drive, read out the fault memory with the 9588 Porsche System Tester II again. Additional causes of faults that could damage the 'transfer box control unit' should be detected and remedied.

DIAGNOSIS TROUBLESHOOTING PROCEDURE

Current sensor in control unit

Note. The current sensor is integrated in the transfer box control unit and can not be separately replaced.

1. Ignition on
2. Internal transfer box control unit function test

1. 'implausible signal'

Transfer box control unit plug

1. Pin

Note. Visual inspection: In the next troubleshooting section, please check first that the affected 'pins' of the transfer box control unit plug connection and the 'pins' of the plug connections on the servo motor are neither damaged nor corroded. Remove any soiling or corrosion/oxidation. Replace damaged parts/wires.

Note. Control unit replacement: Before replacing the 'transfer box control unit', the ground connections, power supply and plug connections on the control unit must be checked as OK. Please observe the coding of the control unit. After the test drive, read out the fault memory again with the Porsche System Tester II No. 9588. Additional causes of faults that could damage the 'transfer box control unit' should be detected and remedied.

DIAGNOSIS TROUBLESHOOTING PROCEDURE

1. Ignition on
2. Internal transfer box control module function test
3. Engine running
4. Selector lever position 'P'
5. Engage longitudinal lock/gear reduction

1. 'Open circuit/short circuit to ground': open circuit/short circuit in wiring harness (brake for servo motor does not activate)
2. 'Open circuit/short circuit to ground': short in servo motor winding (brake) or open circuit/short circuit in servo motor leads (brake for servo motor does not activate)
3. 'Open circuit/short circuit to ground': control unit faulty (brake for servo motor does not activate)

Transfer box control module plug

1. Pin 21 'supply voltage to brake for servo motor (A)', to pin A2 of 'servo motor plug A'
2. Pin 36 'ground supply to brake for servo motor (B)', to pin A3 of 'servo motor plug A'

Note. Visual inspection: In the next troubleshooting section, please check first that the affected 'pins' of the transfer box control unit plug connection and the 'pins' of the plug connections on the servo motor are neither damaged nor corroded. Remove any soiling or corrosion/oxidation. Replace damaged parts/wires.

Note. Control unit replacement: Before replacing the 'transfer box control unit', the ground connections, power supply and plug connections on the control unit must be checked as OK. Please observe the coding of the control module. After the test drive, read out the fault memory with the 9588 Porsche System Tester II again. Additional causes of faults that could damage the 'transfer box control unit' should be detected and remedied.

Troubleshooting fault type: 'electrical fault in electric circuit'

DIAGNOSIS TROUBLESHOOTING PROCEDURE

DIAGNOSIS TROUBLESHOOTING PROCEDURE

Longitudinal lock

Note. After successful read out the fault memory must be erased and after satisfying the diagnostic conditions below must be read out again!

1. Ignition on
2. Internal transfer box control unit function test
3. Vehicle stationary
4. Engine running
5. Brake actuated
6. Selector lever position 'N'
7. Via the left rocker switch on the 'selector switch (running gear control module)', alternately select the functions LOW RANGE and longitudinal lock LOW RANGE 100% (see Driver's Manual)

1. 'Mechanical fault': mechanical wear in transfer box

Transfer box control unit plug

1. Pin '-'

DIAGNOSIS TROUBLESHOOTING PROCEDURE

Poses Online

See also:
• ANTI-LOCK BRAKE SYSTEM (ABS)
• OBD (II)
• FUEL SYSTEM, ELECTRONIC INJECTION
• TIPTRONIC
• AUTOMATIC - ACTUATION, ASSEMBLY HOUSING
• INSTRUMENT CLUSTER
• FINAL DRIVE, DIFFERENTIAL, DIFFERENTIAL LOCK
• 0532