Steering Mounted Controls Communication Module: Service and Repair

Removing And Installing Control Unit For Steering Wheel Electronics

Preliminary work

Preliminary work - Removing and installing control unit for steering wheel electronics
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







CAUTION: Danger of injury and material damage if airbag units are not handled correctly. Always observe the safety regulations for handling airbag units.

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.







- Ensure that arrow -A- of the rotor is positioned between the markings -B- of the arrows -C- of the airbag contact unit and that the locking element -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 rotor 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

Touch up - Removing and installing control unit for steering wheel electronics
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. Calibrate steering angle sensor.

Reading in and reading out data in the control unit for steering wheel electronics

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

INFORMATION:
- If the control unit steering wheel electronics is renewed or exchanged, it must be programmed or coded using the Porsche System Tester. This is to adapt the control unit for steering wheel electronics to the vehicle and equipment.
- If possible, before the control unit for steering wheel electronics is removed and replaced, a read-out of the vehicle data should be obtained from the Porsche System Tester.
- If reading out the data is not possible, the new control unit for steering wheel electronics must be coded.
- The power supply for the Porsche System Tester must be ensured while reading data out and in. A battery charger with a current rating of at least 40 A must be connected to the vehicle battery.
- The Porsche System Tester instructions take precedence and in the event of a discrepancy these are the instructions that must be followed. Deviations may occur with later software versions.
- The procedure described here has been structured in general terms; different texts or additions may appear in the Porsche System Tester.

1. Supply power to the Porsche System Tester via the power supply unit, connect it to the vehicle and start. Switch on ignition. Continue with >>.
2. Select vehicle type. Continue with >> key.
3. Select control unit for steering-column switch and activate with the >> key.
4. Select Control unit replacement and activate with the >> key.
5. Select Read out values and activate with the >> key.
6. The message Coding read-out complete will appear on the screen of the Porsche System Tester. Continue with >> key.
7. Switch off ignition and replace control unit for steering wheel electronics.
8. Switch on ignition. After replacement of the control unit for steering wheel electronics, the vehicle data are installed under the menu Write in data (see Section 6). Continue with >> key.
9. The message Coding write-in complete will appear on the screen of the Porsche System Tester. Continue with >> key.
10. Follow the Porsche System Tester instructions.
11. Read out the fault memory and, if necessary, erase it.
12. Calibrate steering angle sensor.

Coding control unit for steering wheel electronics

INFORMATION:
- During coding, 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.
- The Porsche System Tester instructions take precedence and in the event of a discrepancy these are the instructions that must be followed. Deviations may occur with later software versions.
- The procedure described here has been structured in general terms; different texts or additions may appear in the Porsche System Tester.
- Read out the fault memory and, if necessary, erase it.

1. Connect the Porsche System Tester to the vehicle and start the System Tester. Switch on ignition. Continue with >> key.
2. Select vehicle type. Continue with >> key.
3. Select control unit for steering-column switch and activate with the >> key.
4. Select Coding and activate with the >> key.
5. Select the respective equipment versions and code them.

Coding Setting
Electric steering-wheel adjustment Present/not present
Cruise control Present/not present
Steering wheel Without multi-function steering wheel
With multi-function steering wheel, without steering wheel heating
With multi-function steering wheel, with steering wheel heating

6. Follow the Porsche System Tester instructions.
7. Read out the fault memory and, if necessary, erase it.
8. Calibrate steering angle sensor.

Calibrating steering-angle sensor

INFORMATION:
- The steering-angle sensor must be re-calibrated after exchanging the control unit for steering wheel electronics.
- To correctly calibrate the steering angle sensor, the vehicle must be on the measuring platform.

The steering angle sensor must be calibrated using the menu with Porsche System Tester under the specified test conditions:

Running gear set according to Porsche specifications.

Wheels in straight-ahead position and steering wheel horizontal.

In the straight-ahead position, the steering wheel may be turned by max. ±2.0° from the horizontal position (steering centre position).

1. Connect the Porsche System Tester to the vehicle and start the System Tester. Switch on ignition. Continue with >> key.
2. Select vehicle type. Continue with >> key.
3. Select the PSM control unit and activate using the >> key.
4. Select Actual values and activate with the >> key.
5. Select Security code and activate with the >> key.
6. Note the security code and use the << key to go back to the calibration.
7. Select Calibration and activate with the >> key.
8. Input Security code and activate with the >> key.
9. Activate security code using the F7 key.
10. Select Steering-angle sensor and activate with the >> key.
11. Read safety instructions and activate with the F7 key.
12. After successful calibration, the stored fault code is erased from the fault memory. The PSM indicator light in the instrument cluster goes out.
13. Read out the fault memory and, if necessary, erase it.