Steering Angle Sensor: Testing and Inspection
WM 456005 Initialising and calibrating steering-angle sensor
Tools
Technical values
Checking steering-angle sensor
Initialising steering-angle sensor
NOTICE
Voltage drop
- Fault entries in the control unit
- Coding in the control unit is aborted
-> Prior to disconnecting the control unit, switch off the ignition and remove the ignition key.
-> Ensure that the power supply is not interrupted during programming.
-> Connect a battery charger with a current rating of at least => Nominal value: 40 A to the vehicle battery.
Information
- The steering-angle sensor is integrated into the steering column switch and records the movements of the steering wheel (steering wheel angle). The data is transmitted to the PSM control unit via the CAN bus.
- During initialisation, the steering-angle sensor learns its current position (straight-ahead position).
- Calibration must be performed when working on or carrying out subsequent work on the chassis. This is described in detail in -> 456000 Initialising and calibrating steering-angle sensor - section on "Calibrating".
- The calibration results in zero point balancing (exactly straight ahead).
- The steering-angle sensor is calibrated when first fitted and when any work has been carried out on steering and chassis. Examples of this would be opening the steering wiring and alterations to toe and camber.
- Calibration includes initialisation.
WARNING
Steering-angle sensor not calibrated or calibrated incorrectly
- Unexpected vehicle handling
- Steering-angle sensor does not function
- Malfunction in steering-angle sensor
-> After working on wheel suspension parts, when replacing the steering-angle sensor and after changing the wheel alignment values, calibrate the steering-angle sensor using PIWIS Tester II 9818.
-> Keep the front wheels in straight-ahead position on the measuring platform during calibration.
-> Check the actual value of the steering-angle sensor after suspension alignment where no changes were made to the wheel alignment values.
1. Turn wheels to straight-ahead position.
2. From the straight-ahead position, turn steering wheel approx. 6° to the left and 6° to the right (past straight-ahead position).
Following successful initialisation, the stored fault code is set to "Not present". The PSM indicator light in the instrument cluster goes out.
Adjusting steering-angle sensor
Calibrating steering-angle sensor
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 is replaced.
- Calibration includes initialisation.
- In order to calibrate the steering-angle sensor correctly, the vehicle must be on the measuring platform, the wheel alignment values must be correct and the steering must be in the straight-ahead position.
- Calibrate the steering-angle sensor by selecting >>Steering wheel electronics>>Maintenance/repairs]]Steering-angle sensor calibration[[ in the Porsche System Tester control unit overview.
The steering-angle sensor must be calibrated using the menu options in the Porsche System Tester under the specified test conditions:
1. The chassis is adjusted according to Porsche specifications.
2. Switch on ignition.
3. Wheels in straight-ahead position and steering wheel horizontal.
4. In the straight-ahead position, the steering wheel may be turned by +/- 2.0° from the horizontal position (steering centre position).
5. Enter the safety code under ]] Calibrate [[ in the Porsche System Tester.
6. Turn the steering wheel out of the straight-ahead position (approx. 6° to the left/right) in accordance with the instructions on the Porsche System Tester. Turn the wheels back to the straight-ahead position and follow the instructions on the Porsche System Tester.
7. After successful calibration, the stored fault code is erased from the fault memory. The PSM indicator light in the instrument cluster goes out.