R1200GSA 2010 Secondary Stick Coil U/S

[Stuart Dorey]

I (and my local BMW dealer) are at our wits end on fault finding this one. This is the first time I have posted but just wondering if any of your members may be able to shed some light on the possible cause - the secondary stick coil on No 1 (n/s) is not sparking.

We have tried swopping over coils and also BMSK units from 2 donor bikes but the problem persists. We also put my BMS unit onto one of the donor bikes and interestingly the fault transferred across.

We have opened up the loom and physically traced/inspected the wiring to the coil and no damage seen (continuity and ohms check across the 4 coils are the same).

Any advice/ideas welcomed?

[mike d]

Hi Stuart,

It's interesting that the fault transfers when the BMS unit was swapped to another bike. Did this other bike perform o.k. with its own controller fitted?

Mike D (BMW Club Tool hire)

[Stuart Dorey]

Hi Mike

Nice to hear from you. Yes both donor bikes performed ok prior to and after their BMS units were removed (to try on my bike) and subsequently refitted.

On my bike the above fault persisted despite having fitted a BMS unit from each of these other bikes. That led us to believe that my BMS unit was ok and the cause of the fault was elsewhere and so we split the wiring loom open to enable us to physically trace and inspect the wiring. The earth on the coils is common and as the other 3 work ok this rules out a bad earth.

After confirming that there were no wiring faults, we decided to try putting my BMS unit onto one of the donor bikes and were surprised to find that the fault transferred across to the other bike (the fault thankfully cleared after it's original BMS was replaced). This clearly raised suspicion again over my BMS unit except fitment of a BMS unit from 2 donor bikes did not rectify the fault (no spark).

The other unit (ZFE) was not switched and I am wondering whether this unit may be faulty?