Steering - EPS Lamp ON/Steering Angle Sensor DTC Set
SI B32 15 05Steering and Wheel Alignment
October 2005
Technical Service
SUBJECT
Steering Angle Sensor Faults
MODEL
E85 (Z4 Roadster)
SITUATION
Customer may complain of illuminated Electric Power Steering (EPS) warning lamp when driving the vehicle. Steering Angle Sensor (LWS) fault code may be stored in EPS and/or DSC control module.
CAUSE
EPS has no servo assist when an under voltage condition is detected, i.e. less than 9V. Servo assist returns to normal when the voltage is more than 10V. When the fault is no longer present, the EPS warning lamp will stop illuminating.
CORRECTION
In case of a customer complaint, check the battery condition and calibrate the steering angle sensor.
PROCEDURE
1. Check the battery condition using approved BMW Battery Tester (see SI B04 25 02). Please also refer to related Service Information: B61 08 03 "Looking After Your Vehicle Battery", B61 16 00 "Battery Maintenance", B61 205 04 "Battery Discharge with Key Inserted in Ignition Lock" and B61 206 03 "Battery Discharged: SMG Transmission".
2. Clear the fault code once the battery is determined to be in an acceptable condition.
3. Calibrate the Steering Angle Sensor.
4. If the fault returns or the LWS cannot be calibrated, replace the LWS only and do not replace the EPS unit.
5. Follow Repair Instructions RA 32 31 082 to replace the LWS.
WARRANTY INFORMATION
Information only