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Multi System Failure!

Tuesday 5th April 2016
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Recently, we have received several calls form garages relating to various fault lights on the BMW X3 E83.
    The SRS, ABS/DSC and 4X4 system warnings lights are illuminated. On investigation, the main code seems to be the LEW sensor, or commonly known as the Steering Angle Sensor. But the other systems are reporting corrupted data from ABS/DSC module.
    Fault codes presented are F50C in the ABS system,as well as 5EB1, both refering to Steering Angle Sensor. The sensor power and ground connections are checked, and are all good. CAN signals present at the sensor are good. But the sensor is communicating as a separate module. The sensor has it's own K line connection and reported no faults. There is no live date showing angle movement on the scan tool.
    So a new sensor is fitted, mounted half way down the steering column requiring the lower and upper parts to be separated.
    On fitting the new LEW sensor, data is checked only to find no data is being displayed from the ABS/DSC module for steering angle. This has now got the technician doubting his diagnosis.
    The scan equipment he was using did not have the ability to program a new component into the ABS /DSC, so the steering angle reset failed. Not until the sensor had been programmed using suitable equipment, and the a steering angle calibration performed, does the sensor start to display the expected data.
    Once this was completed, codes from the SRS system, 4X4 system, ABS and DSC were deleted and all the warning lights for the three systems went out.
    This only enforces the problem garages are having with systems that rely on sharing sensor information to function correctly. ABS/DSC braking, SRS and 4X4 transfer modules all looking for steering angle information to be present on the CAN network before they can perform their individual tasks.