I'm pretty conversant with the brake systems on the 1150's and 1200's. done a lot of flushes, pads, yada yada. But right now I'm stumped. My teenage son took his bike in some mud and got stuck up to the center of the final drive. His light on the dash immediately went on with brakes barely working. When he got it home I did all the normal checks... Fluid level, no interference with the lever or pedal, mud in the front abs ring, calipers, etc and found his rear bulb was out. I know from past experience that can throw off the whole system. I excitedly replaced the bulb but still no dice. I actually haven't taken it off the lift to run it for the customary 2 feet but the bulb is still solidly lit with no change when applying brakes. For sure I want to flush the whole system because I know the previous owner never did and who knows about the original owner. In the meantime, anyone have any suggestions?
Flush it first. Does the speedo work correctly? Most likely mud or rub damage from mud to the sensor(s). Likely front if the speedo works. Jim
Have him check the brake light switches. Had the same thing happen on my '05 R1200ST; the brake warning light, and no power assist. It ended up being bug juice & grime made the micro switch stick on at the front brake lever, which in turn shut off the power assist. I cleaned out the spuge, dead bugs, 'n grime, and it worked fine after that.
So far no dice on your suggestions. The brake sensor looked virgin. I pulled I out and saw there was some fluid on the end. I assume that was because it is the filling hole for the FD fluid. Next, tactic is full brake flush.
This ^^^ Make sure you can hear the "click" of the switch and that brake light goes on when front and rear brake levers are actuated. You wrote that the bulb is lit, but I am not sure if you meant warning light or the rear brake light. Did the bike stall in the mud? That is, did the warning light come on while the bike was still running, or was it after restart?
That may be the clue you are loooking for. You may want to check out the rear brake switch - that's most likely where some damage could occur. Normally, brake lights go on/off with the switches - even before completing the self check. I am looking at the wiring diagram: the rear brake switch has two wires coming out: Yellow/Black and Yellow, going to a 2-pole connector before heading up to the ZFE (chassis controller). According to the diagram, the connector is zip-tied to the crossbar, just forward of the upper rear shock mount. Open up the connection and measure with ohmmeter whether the switch closes circuit.
Ok... I thought I was proficient until you start talking volt meter on the zebra con to the 5.3rd power. I am humbled. When I get to the bike ill compare your post to whatnot can see. Thx for helping.
Aw, c'mon - courage! If you handle wrenches, you surely can deal with an electrical meter. You'll have no trouble. In my mind, the biggest problem for you will be to find the connector. The diagram shows it just ahead of the top of rear shock, either zipped to frame crossbar or to a wire guide. Look for a 2-wire connector with the yellow/yellow-black colors mentioned above. To test: plug (DELICATELY) an ohmmeter (continuity tester) into the part going toward the brake switch. Make sure you are certain about which part you test. Operate foot brake, circuit should change state, open/close. If that fails, you could try checking the connection going toward the ZFE computer: use some very thin wire to (DELICATELY) short out the connector; the brake light should come on. Remember that the problem could be completely elsewhere; this is just one of the items I'd check. After all, your son was trashing the bike around, there are many items that could be subjected to damage. The clue for me is that your brake light is always on. The light is controlled by the chassis computer, ZFE, which senses the lever switches and turns on the light. This is unrelated to ABS computer, which operates by sensing fluid pressure (it's a bit more complicated, but you get the idea). Regarding the test set: it's best to use a DMM (digital multimeter) because the sense current is limited and you are minimizing the risk of damage if you plug it into a wrong circuit. A handheld analog multimeter is next best thing. NEVER use a 12v test light - these use own battery and can allow a lot of current. If you touch a wrong circuit, you could burn it out. I hope this helps. R.
CONGRATULATIONS! It's amazing how finding a broken part can make you happy (when you were worried about a $2k ABS repair). I cannot orient myself in your photo. Is this near the swingarm, taken from underneath?
That wire is on the other side of the frame from the pivot point on the rear brake pedal. I guess when he synch into mud and rock, one of the wires got sheared off. I've never heard I rhy happening before. I'm going to try to fabricated some sir of armor on his and my. 2011gsa.
Hey Brian, saw your post and thought I would say Hi! How are things in Cincy? Any scars left from the BMW training center? DH
