ABS Problem ??

[ALHTHS]

I have noticed than when I start the bike some times the ABS lights are flashing alternative (as opposed to flashing simultaneously) and some times the stay on. The result is when I drive away they stay flashing alternative (or they stay on) which means the ABS system has not activated. I have noticed that this is "a roll of the dice" situation as sometimes it works and some times not.

Has anybody else experienced the same?

 

[Greg Masters]

This is a very well-known problem that affects pre-servo brake bikes.

The root cause is the design of the ABS circuitry which requires a certain voltage to engage. If this voltage is not maintained because of a less than tip-top battery (especially when starting and/or cold conditions), the ABS can drop-out into 'fail' mode.

BMW will tell you that it's designed this way for your own safety - although there's a leap of logic in that argument which I don't follow.

There are a number of solutions possible:

• Run your bike for a few minutes, then turn off the engine and restart. That usually works.
• Fit a brand new battery. That sometimes works, although my R1100GS failed when it was 1 day old!
• Buy an Optimate (or similar) and use it at every opportunity.

Greg

 

[Rabbitson]

Also see here:

www.ukgser.com/forums/showthread.php?s=&threadid=13127

www.ukgser.com/forums/showthread.php?s=&threadid=14588

HTH,

David

 

[(RIP) maverick]

Mine does exactly the same in the winter months, now that it gets warmer seems to be ok unless it does not start the first time. It does seem like the battery but will wait for that to die completely or 10% discount next month at the BMF

 

[ALHTHS]

Sorry I forgot to mention that my GS is a 2002 model and I always have a charger connected when not riding.

 

[Broadslideronnie]

I purchased a 99 1150GS recently and had exactly the same problem.
I suspected the battery and it was cured with a new battery as the old one was the original.
Ronnie.