K12LT ABS and diagnose connector

[dan cata]

Hi all,

 

I have a friend that purchased a k1200lt, 2000. This is his first street bike, so he does not know too much about BMW's.

 

The guy that sold him the bike, knew that it had ABS related issues, so what he did was to take out the bulbs in the ABS sockets in the dash. Yes...

 

So my friend got it and after a while he realized what happen.

 

First thing was to connect the gs911 and saw this:

 

 

I installed the bulbs in the dash and then reset the errors.

When switching the ignition on, both lights started to flash at the same time, normal. So I took it out for a ride.

 

After takeoff, instead of the clunk! sound, the lights started to flash alternatively... I read the errors once again and got this:

 

 

I have been doing some reading on advrider about this and really don't know where to start. I changed the brake fluid,the old one was brownish, but that did not cure the problem.

 

i do have access to another ABS unit from another k1200lt that supposedly is mechanically OK, just a faulty electric part, so I could swap the electric part from this bike to that one. Another possibility is the big relay for the motor, but I really doubt it. A failed relay would just drive the motor even if the ignition is switched off, AFAIK.

 

Just wondering if this has happened to any of you and what did you do about it, where should I start...

 

Another thing that intrigues me is the diagnose cap, it had this on the inside. Never saw it, does someone know what it does?

 

 

 

Thanks,

Dan.

 

[dirtrider]

Morning Dan

 

It could be a power relay problem but that usually gives that code also (not stuck shut but failed open).

 

The usual problem with a stuck piston code is (well a stuck piston) or a displacement sensor not working correctly.

 

If you can figure out how to do a pressure test & pressure hold that m-i-g-h-t free a stick piston but usually doesn't.

 

The other alternative is to take the controller apart & clean the pistons & piston bores. (there are some on-line procedures if you look for them)

 

[dan cata]

Hi,

 

Today I took the 2 bleeders off the ABS unit off, removed the pistons, cleaned them and put them back in, changed the brake fluid and then, when trying to ride it, the bulb lights again started to flash alternately... I still get the 13 - plunger test fault. Worked all day on this and still nothing.

 

The truth is that I really don't know how this system works. Is there some tutorial about it, apart from the one on advrider?

 

Does anyone have any suggestion to this apart from changing the unit?

 

Thanks,

Dan.

[Carnadero]

Does anyone have any suggestion to this apart from changing the unit?

The K1200LT forums site would be a good place to dig for more information...

[dan cata]

I did search about the ABS 2 on google a lot, and it was not in vain.

 

I was able to have it fixed, not sure how I did it though...

 

The rear circuit had old and brownish brake fluid, so I assumed the issue was from there. I replaced the brake fluid for 3 times in the end. Also, I changed the small spring that sits above the metal ball and upon takeoff, I kept the rear brake On. The lights stopped flashing and the bike's ABS started to work again. Only tested it on the rear side, but I am assuming it should work on the front side as well.

 

Could not have done this w/o the article on advrider about ABS2 and my GS911 diagnose unit came in handy for resetting the error codes, otherwise I would have to build a reset button on the bike, and loose some time with that too.

 

Thanks all!

 

Dan.

[dan cata]

I observed it passed 2 month since I started this topic. Yesterday, I got that bike fixed. I had to get an used ABS unit from ebay. The problem is that BMW (shame on them!!!) makes these units totally different. Even though they might look the same, the brain/ electrical parts are not. The good thing is that the electrical parts can be swapped from the broken unit to the donor unit, using just a tri-wing bit.

 

The not so good part is that the brake fluid lines coming in and out from the ABS unit have different sizes and threads. There are 4 of those on each ABS 2.2 unit: in for front, out for front, in for rear and out for rear. The front side was OK, but as for the rear, they have interchanged the metal line screws between them. The donor unit was from a k1200rs bike. I figured if I get the lines from a k1200, it would work. It didn't work, at least not that easy.

 

So when getting used ABS units, make sure you get it from the same bike as yours and the same year. I have noticed that they have different codes even between same bikes but other years.

 

Dan.