Steering Mounted Controls Communication Module: Service and Repair

Removing And Installing Control Unit For Steering Wheel Electronics

Tools







Preliminary work
1. Remove driver's airbag unit.
2. Remove steering wheel.
3. Remove steering column trim.
4. Remove steering column switch.

Removing control unit for steering wheel electronics

INFORMATION:
- The control unit for steering wheel electronics is bolted to the steering-column switch.
- Before the ground strap of the battery is disconnected, the data in the control unit for steering wheel electronics must be read out using the Porsche System Tester.







INFORMATION: Ensure that the arrow -A- of the rotor is positioned between the markings -B- of the arrows -C- of the airbag contact unit and that the latch -D- is engaged.

1. Remove contact unit.







1.1. Carefully lift up the three retaining tabs and remove airbag contact unit.

2. Unscrew fastening screws for steering wheel electronics control unit.







2.1. Unscrew the five fastening screws.

3. Push out the line holder.







3.1. Push line holder down and out of the steering-column switch.

4. Remove control unit for steering wheel electronics.







4.1. Turn steering column switch round and remove control unit for steering wheel electronics.

Installing control unit for steering wheel electronics

WARNING:
Risk of damaging airbag contact unit.
- If the airbag contact unit has been adjusted, proceed in accordance with the following work instruction:

- To position the airbag contact unit in the central position, press the locking element and turn the motor carefully to the left as far as it will go.
- Then turn the rotor carefully to the right, approx. 3.5 to 3.75 revolutions, until the band printed on one side is visible in the window.

1. Install control unit for steering wheel electronics.







1.1. Position control unit for steering wheel electronics on the steering-column switch.

2. Push on line holder.







2.1. Push line holder onto steering-column switch.

3. Unscrew fastening screws for steering wheel electronics control unit







3.1. Turn the steering column switch round and screw in the five fastening screws.

4. Install contact unit.







4.1. Position airbag contact unit and press onto the steering column switch until the three tabs are felt to engage.

Subsequent work
1. Install steering column switch.
2. Install steering column trim.
3. Install steering wheel.
4. Install driver's airbag unit.
5. Read data into the control unit for steering wheel electronics.
6. Calibrating steering angle sensor.

Reading data out of and writing data into the control unit for steering wheel electronics

Reading and printing values

INFORMATION:
- If reading out the data is not possible, the new control unit for steering wheel electronics must be coded.
- The PIWIS Tester 9718 instructions take precedence since the description may be different. This may be due to more recent software versions.
- The procedure described here has been structured in general terms; different text or additions may appear in the PIWIS Tester 9718.

WARNING:
Sudden voltage interruption of the power supply to the control module.
- Destruction of the control module.

- During programming, it is essential to guarantee the power supply for the Porsche System tester. It is essential to connect a battery charger with a current rating of at least 40 A to the vehicle battery.
- Prior to disconnecting the control module, switch off the ignition and remove the ignition key.

1. Connect the Porsche System Tester to the vehicle and start the System Tester. Switch on ignition. >> Continue.
2. Select the vehicle type.
3. Switch from the vehicle type to the list of control units.
4. Select steering wheel electronics with the cursor keys and press the >> key.
5. Select Control unit replacement with the cursor keys and press the >> key.
6. Select Read out values (codings) with the cursor keys and press the >> key.
7. The message Codes successfully read out appears on the screen of the Porsche System Tester. Press >>.
8. Switch off ignition and replace control unit.
9. Switch to the Special functions menu and perform the vehicle handover using the F8 key.
10. In the Special functions menu, erase All fault memories by pressing >>.
11. Carry out automatic search of control units.
12. In the menu Write in data >> , the data read-out is installed.
13. System tester displays Coding write-in complete >>.
14. Change to the Coding menu and compare the coding with the vehicle equipment. Recode if necessary.\
15. Quit menu, carry out a test drive, and read out fault memory.

Coding control unit for steering wheel electronics

INFORMATION:
- The procedure described must be applied when a control unit has to be replaced and the tester function Control unit replacement cannot be used.
- The PIWIS Tester 9718 instructions take precedence since the description may be different. This may be due to more recent software versions.
- The procedure described here has been structured in general terms; different text or additions may appear in the PIWIS Tester 9718.

WARNING:
Sudden voltage interruption of the power supply to the control module.
- Destruction of the control module.

- During programming, it is essential to guarantee the power supply for the Porsche System tester. It is essential to connect a battery charger with a current rating of at least 40 A to the vehicle battery.
- Prior to disconnecting the control module, switch off the ignition and remove the ignition key.

1. Connect the PIWIS tester 9718 to the vehicle and start it. Switch on the ignition. >> Continue.
2. Select the vehicle type.
3. Switch to the Special functions menu and perform the vehicle handover using the F8 key.
4. In the Special functions menu, erase All fault memories by pressing >>.
5. Carry out automatic search of control units.
6. Using the >> key, move from the vehicle type to the list of control units.
7. Select the control unit Steering wheel electronics and activate with the >> key.
8. Select Coding and activate with the >> key.
9. Select the respective equipment versions and code them.

Coding Setting
Tiptronic yes/no
Multi-function steering wheel yes/no
Cruise control yes/no
Headlight washing system yes/no
Push-to-talk yes/no
Rear wiper/washer system yes/no

10. Follow the instructions on the Tester.
11. Calibrate steering angle sensor.
12. Carry out a test drive and read out fault memory.

Calibrating steering-angle sensor
The steering angle sensor must be calibrated using the menu with PIWIS tester under the specified test conditions:

WARNING:
Sudden voltage interruption of the power supply to the control module.
- Destruction of the control module.

- During programming, it is essential to guarantee the power supply for the Porsche System tester. It is essential to connect a battery charger with a current rating of at least 40 A to the vehicle battery.
- Prior to disconnecting the control module, switch off the ignition and remove the ignition key.

INFORMATION:
- The steering-angle sensor must be recalibrated on the measuring platform following repairs to or work on the chassis/steering or if the steering-angle sensor/steering column switch/hydraulic unit is replaced.
- In order to be able to calibrate the steering angle sensor correctly, the vehicle must be on the measuring platform, the wheel alignment values correct and the steering in the straight-ahead position.
- The security code is displayed in the Porsche System Tester under menu PSM, Actual values, Security code.
- The PIWIS Tester 9718 instructions take precedence since the description may be different. This may be due to more recent software versions.
- The procedure described here has been structured in general terms; different text or additions may appear in the PIWIS Tester 9718.

1. Switch on ignition.
2. PIWIS Tester 9718 must be connected to the vehicle before starting it. Switch on the ignition and press >> to continue.
3. Select the vehicle type.
4. Select the PSM control unit and press >>.
5. Select the Actual values menu and press >>.

INFORMATION: In the straight-ahead position, the steering wheel must deviate by no more than ± 2.0° from the horizontal position (steering centre position).

6. Turn wheels or steering wheel to straight-ahead position.

Select the Security code actual value, and press >>.

7. Write down security code. Press << to return to the PSM function selection.
8. Select the Calibration menu item, then enter the security code you wrote down, and press >>.
9. Confirm the security code by pressing F7.
10. Steering-angle sensor must be selected, then press >>.
11. Before calibrating, first turn the steering wheel from the straight-ahead position approx. 20° to the left and 20° to the right (past straight-ahead position).

INFORMATION: In the straight-ahead position, the steering wheel must deviate by no more than ± 2.0° from the horizontal position (steering centre position).

12. Turn wheels or steering wheel to straight-ahead position.
13. If the wheels are in the straight-ahead position, press >>.
14. Tester confirms Calibration successful.
15. Carry out a test drive and read out fault memory.