[Ob1knbxtrail]

UK spec F25 second gen with adaptive Xenon headlamps and LED rings.

Amber dash warning message appeared saying Side Light/DRL failure and LED rings on RHS headlamp no longer working. LHS headlamp is OK. Main xenons still function OK. This suggests it is a partial failure of the TMS Headlight Ballast module? As the car is out of UK warranty, I am keen to diagnose myself rather than be told by a dealer to pay over £1000 plus fitting for a new complete headlamp module.

Can anyone advise if it is possible just to swap over the ballast modules between the two headlight units to see if the fault is in the module? If the fault moves to the LHS when I swap modules over then I will know it is the offending part. Problem is every part in a BMW seems coded to a car. Apparently the module needs coded to the VIN of the vehicle (?) but are they also specifically coded for LHS and RHS?

Kind of annoying that faults like this appear on a car that is only 3.5 years old and less than 30,000 miles but I guess that is the penalty for all this technology!

Any advice greatly appreciated

William