• Welcome, Guest! We hope you enjoy the excellent technical knowledge, event information and discussions that the BMW MOA forum provides. Some forum content will be hidden from you if you remain logged out. If you want to view all content, please click the 'Log in' button above and enter your BMW MOA username and password.

    If you are not an MOA member, why not take the time to join the club, so you can enjoy posting on the forum, the BMW Owners News magazine, and all of the discounts and benefits the BMW MOA offers?

ABS light flashing and brakes are not working

bbowers

New member
After plugging in my GPS to my 2005 K1200S yesterday, I accidentally allowed it to draw a charge from the bike for about an hour (bike was not running). When I went to start the bike with the GPS plugged in, the ABS light flashed extremely fast and the brakes stopped working. I shut off the bike, unplug the GPS, and the bike ran as normal (ABS cycled through its function check, the ABS light went out, and I had brakes).

I went on a long ride and attempted to plug in the GPS again. When I started the bike, I again had a fast flashing ABS light and no brakes. I shut off the bike, unplug the GPS, started the bike and I still had a fast flashing ABS light and no brakes.

I shut it down for the night and the next morning it started up and I now have brakes. I have not attempted to plug in the GPS.

So clearly the battery is the culprit to my brake problem. Why? Did I run the battery down too much by accidentally charging the GPS off the battery when the bike was not running? Do I need to replace the battery or can I simply put it on charger for several hours? Should I use a charger or a battery tender?

Any advice is appreciated. Thanks.
 
Last edited:
Brakes and battery

You should be able to run phone charger, gps and a few things off battery with motor off without running it down, couple days even. Put meter to battery and see what volts are reading. Below 12v Battery may be toast if a few years old. I like the AGM battery for climate changes and long life, every three years it seems. Under $100 for battery (Batteries Plus, or on line) and lots of peace of mind on trips or when you get up and ride.


Cheers,


Miles
 
Thanks. I put it on the charger overnight. I guess I'm trying to figure out if my lack of brakes (actually, I still have about 20% brakes) is related to a battery problem. Specifically, did my negligently charging my GPS for an hour off of the battery when the bike was not running deplete the battery to a point that it could not recover and consistently power the brakes? Adding to the issue, if the bike would sit for a few hours, I could start it up and I'd have brakes. Then, after a while, the ABS light would begin flashing and I'd no longer have brakes. These issues started immediately after I charged the GPS on the non-running bike.
 
Thanks. I put it on the charger overnight. I guess I'm trying to figure out if my lack of brakes (actually, I still have about 20% brakes) is related to a battery problem. Specifically, did my negligently charging my GPS for an hour off of the battery when the bike was not running deplete the battery to a point that it could not recover and consistently power the brakes? Adding to the issue, if the bike would sit for a few hours, I could start it up and I'd have brakes. Then, after a while, the ABS light would begin flashing and I'd no longer have brakes. These issues started immediately after I charged the GPS on the non-running bike.

A weak battery will cause the servo units to not run, leaving you with reduced braking power. ABS may also not be working.
Running the GPS for a few hours should not drain the bike battery, but maybe the battery is on it's last leg.
Do you have a shop close by that can do a load test on the battery?
How old is the battery?
 
Battery?

So clearly the battery is the culprit to my brake problem.

Respectfully, the ABS light almost always clears with power-reset. The codes stored internally don't: you should get those checked before concluding the battery was your only fault here.

And just in case you need it, Module Masters FTW.
 
Back
Top