BMW R1200R R1150R/T F800 K1200R R1100R/T R1250R RnineT Message Board

Any fix for low voltage sensitive ABS control unit. It is a 1995 R1100R with 22k miles, two and a half year old battery.

Especially on cold weather, battery voltage will dip south of 9V , on start-up, and the ABS light will flash in alternating fashion.

I tested Battery and is getting 300 CCA (listed at 275 CCA), "idle" voltage is 12.85V and that is after a few days of seating. It was doing the same thing when the battery was a few months old. If I use lighter engine oil (less than 20W50) things get a bit better.
Anybody with any ides better than worming up the engine and than restarting it again??

Over on the IBMWR site there's some help posted specifically for this chronic ABS problem so I'll post it here for others looking for such info. It's unfortunate such nice bikes have had long-standing major problems with this and surging without the company stepping in with some upgrade fixes. The modification below might take some guts, but not a lot of technical skill. It's one of those "do it on your own but don't blame me if it doesn't work or if you bike starts sending diagnostic smoke signals or if you hear a swan singing".

http://www.ibmwr.org/r-tech/oilheads/AB ... ndex.shtml

If you have a good battery, then I would keep it on a Battery Tender.
Have a BT for my R and RT....no problems at all.

A very excellent battery charger does come with the motorcycle. Perhaps you're having some trouble locating it. It's round, black, rubber, and rests beneath your right palm. Easy and fun to use, too.

Have you possibly got some farkle either powered or relayed from the brake circuit? Flashing LED brake lights, or some other accessory lighting?

I will put it this way...

1. Boxers are heavy on batteries
2. Any battery over two years old is a bonus
3. Batteries are like babies and need warmth
4. ABS is sensitive to low battery voltage and always have been
5. Check the shim spacing on the ABS wheel sensors
6. Check the charging voltages with the engine running at 2000 RPM it should be around 13.8-14.2volts

try this out and let me know the results and we can work from there...

cheers arbee

Larryboxerguy wrote:Over on the IBMWR site there's some help posted specifically for this chronic ABS problem .......
http://www.ibmwr.org/r-tech/oilheads/AB ... ndex.shtml

Chronic indeed. It was the 1st "BMWism" (sure they aren't made in Italy?) that I experienced with my new to me r1100r. After searching the net, it is indeed epidemic, albeit not as big a deal as the other fish we have to fry, i.e. ghost neutrals, final drive and clutch spline issues. I love my bike, but if I knew then what I know know...well, I might just be on something else. That said, I love the bike and thanks for the link. It looks like a winner.

Thank you for the replays. It is definitively something related to the early ABS systems, they were just the same on the cars at that era. ( I was BMW master tech beck then, on cars).

All electrical system works just fine. I do believe the battery is showing a bit of age, but it started just a few mounts after was replaced. So if I put on the new one it will be good until next fall and as soon the oil get up in viscosity I will need new one again!!

I like the idea from the IBMWR and I will try it as soon as I get some time. It due for the 24K service, so when I remove the tank I can replace the fuel filter at the same time.

I will keep you posted with the outcome of modification.