The cause of the problem was starting the bike with the front brake hard on from holding it while wife was climbing on and a sticking brake light switch. The computer thought the brakes were on so could not complete its tests and TO BE SAFE went into residual mode. When the switch eventually turned the brake lights off the test completed and the normal braking returned.
So it was caused by "user error."
Good for you for having the honesty to admit that here.
There seem to be several possible causes for these "failures:"
Manufacturing error: Such as that stated (above) where there is an issue with the pipes. BMW Servo brakes are not the only systems prone to error. It would be nice to think that such important features such as brakes are devoid of such possibilities but the process involves humans, errors are inevitable.
Component failure: Any component can fail. It may be due to improper use (see "user error below) or manufacturing error (above).
User error: Not understanding or ignorance of the manufacturers instructions.
I have an 04 1150 GSA. It has BMW Evo-III, semi-linked Servo/ABS. The system is more complex than any brakes I've found fitted to any other bike I've owned, including earlier ABS equipped BMW's.
The bike has done 30,000 (mainly touring) miles.
In that time, the only issues I've had with the system were when the original battery was giving-up. There was insufficient juice on start-up, so the ABS was by-passed. A nice big red light warned me that I had no ABS and stopping after about ten minutes, re-starting, returned all to 'normal.'
I wasn't surprised by this, I wasn't concerned that the brakes would fail because I'd read the manual.
Likewise, having read the manual, I know that I have to allow the system to cycle through its various tests before pressing the starter or operating either brake lever. I don't find keeping to the instructions difficult.
I have to admit that I have been affected by all these failure stories. As a result, if you are ever following me, you may see my brake light come on momentarily a long way from the normal braking point. That's me just reassuring myself that everything is fine before I use the brakes properly! (If I'd never read any of these stories, I'd blithely do what I used to do and wait to touch the brakes when I need them).
I do wonder in the light of andyclift's post, whether those who have suffered fatal consequences, did something similar to him? Did they allow the system checks each time? Were they a "rear brake dragger?" (I've seen quite a few riders whose brake light is permanently on because their foot is on the brake pedal).
The trouble is of course that people rarely admit their errors, especially those that are seeking compensation. Then there are those that unfortunately are unable to be asked.
Now we have "fault code" storage and lack of fault codes is in itself being added to the mix.
It seems perfectly logical to me, that where a fault is caused by the user and then remedied either by the system or the user not repeating the error, that no fault is lodged.
Would owners be prepared to pay for the added workshop time caused by BMW searching for faults that no longer exist?
The Servo-ABS set-up is complex, some would say unnecessarily so and that's a debate that will rage forever. The 1200 models have added to this complexity by having a system that has in the past caused batteries to drain by brake levers touching handguards or owners pressing an indicator switch within a short time of switching off the ignition.
It just strikes me that it has become even more important for owners to understand their machine.
There's still no substitute for
