The dreaded "Lighting System" Error. Usually during diagnostics, the Foot Rest Module (FRM) will not communicate. This typically happens after a discharged/replaced battery and in some cases, has been linked to a diagnostic session with BMW's ISTA Software. When this occurs, many of the Lighting Systems stop functioning as well as the Power Windows and other features controlled by the FRM.
This has been very problematic for BMW, so much that they issued an Extended Warranty on most of these. However, a majority of the vehicles effected are well outside of the Extended Warranty period and those that are covered, have to wait for an available appointment at the dealer and FRMs frequently go on back order (weeks or months at a time).
Obviously this presents a major issue for shops and customers alike. Customer's might experience a flat battery and end up with a partially disabled car once running again. Shops may see FRM failures while trying to diagnose an completely unrelated concern.
Regardless of where the FRM failed, the most common issue is a corrupted memory device on the circuit board. We have learned how to repair this issue without replacing any parts (new FRM is over $500 not including labor/programming).
To fix, we first remove the FRM from the vehicle. Since the FRM no longer communicates via the OBD Port, reading flash data is done directly from the Circuit Board.
Once we manually pull the Flash Data, we can rebuild the EEPROM Data, which has become corrupted. There are many places you can mail your FRM to get repaired like this, but because "time is money" and we know the customers appreciate a quick turnaround, we do all of this work in our shop.
