Initialize steering-angle sensor
CAUTION:
Increased risk of accident whenever power supply is interrupted. PSM does not function.
→ The steering-angle sensor must be initialized (taught) whenever the battery is disconnected.
NOTE:
- The steering-angle sensor is integrated into the steering column switch and records the movements of the steering wheel (steering wheel angle) using light switches. The data is transmitted to the PSM control unit via the CAN bus.
- During initialization, the steering-angle sensor learns its current position (straight-ahead position).
- The steering-angle sensor must always be initialized if terminal 30 was interrupted (for example, battery replacement, undervoltage, steering column switch disconnected, relevant fuse removed)!
- Calibration must be performed when working on or carrying out subsequent work on the chassis. This is described in detail in the next chapter. Refer to 45 60 05 Initializing and calibrating steering angle sensor - as of MY 2003 (All Models) .
- 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 initialization.
1. Turn wheels to straight-ahead position.
2. Start engine.
3. From the straight-ahead position, turn steering wheel approx. 20° to the left and 20° to the right (past straight-ahead position).
4. Drive the vehicle straight ahead for at least one second at a speed of over 4 km/h (2.5 mph).
Following successful initialization, the stored fault code is set to "Not present". The PSM indicator light in the instrument cluster goes out.
CAUTION:
Increased risk of accident if the battery is disconnected after initializing and/or the relevant fuse is removed. There must be no undervoltage during the process.
→ Every time the battery is disconnected, the relevant fuse removed or an undervoltage is present, the steering-angle sensor must be initialized (taught).