[Wheelsca]

I was wondering if anyone could help me out. I have a 2005 1200rt, purchased the bike in January and the ABS light would go out when the bike started moving. I completed a brake system flush and all seemed good. When I got the bike out last week the ABS light and warning signal we flashing once per second. I hooked up my GS911 and it says the fault is low fluid level. I have checked all four reservoirs and they are all filled to max. If I erase the code then it just comes back. Riding the bike the ABS system is working perfectly. Has anyone come across this problem before.

 

[OU812]

How old is your battery?

 

[Wheelsca]

I don't know the age of the battery. I had it on a maintenance charger all winter and it starts the bike easily.

 

[gr8ridn]

Check both fluid level sensor connections on top of the brake module. They both should be closed circuit and are wired in series. If either is open (with adequate fluid) this will signal the fluid level fault. Brake fluid sensor failures are fairly rare. I would check the sensor continuity and connector condition.

 

[David13]

At some point, I don't know what point, the GS911 can detect (if it is set) a low voltage condition, which should result from ... a bad battery?
dc

 

[Wheelsca]

The GS911 is not telling me there is a low voltage condition.

 

[deanwoolsey]

Check for rat damage if the bike was stored over the winter in a shed or barn. Could be a cut wire.

Also, if you got air in the system you may need to bleed the main ABS unit.

 

[Wheelsca]

Wires look good, no rodent damage.

Gr8ridn

Thanks for the tip I will check it out, it gives me something to go on.
Nice to know the sensors are reliable and how they are wired.

Thanks

 

[Wheelsca]

Dean I also wanted to mention air isn't a problem, the system passed the GS911 pressure test.

 

[beech]

Your year bike has a complicated ABS/brake servo system. The bleed procedure is not for the faint of heart. You do not mention if you are knowledgeable of the servo bleed technique. I don't want to offend but here it is. If not followed, it can lead to the situation you are in.
http://www.beachbus.net/BMW/diy/Bleed_Wheel_Circuits.htm
http://www.beachbus.net/BMW/diy/Bleed_Control_Circuit.htm
As you can see there are two circuits for each end of the bike, total of four systems to bleed (with 4 fluid levels to maintain and check). It can be done by the home mechanic but it benefits to have a GS-911 to do the bleed pressure test after you have completed everything. I have done it with out the 911 test and there is no problem if you never let any air into the systems.

 

[New2rt]

Checking the level sensor circuit should get you where you need to be.


Here is another bleed procedure - http://advwisdom.hogranch.com/Wisdom/service_abs3.pdf

 

[Wheelsca]

Problem solved

First I just want to say thanks for all of your replies.

When flushing the brake system I had removed the main abs computer plug.
When everything went together for some reason the fluid level sensor circuit didn't make a good contact. Removed the plug and reinstalled and all is good.

Thanks again Doug

 

[beech]

Good deal, thanks for getting back with the resolution.

 

[David13]

That's the best way. Try the simple stuff first.
And back track on all you did. And then, reconnect all connectors.
dc