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Speedometer/ABS not working after jumpstart and new battery

895 Views 4 Replies 4 Participants Last post by  sturgeon
I have a 2007 R1200R and had a battery that was reaching the end of its life and wouldn’t hold a charge. I was hoping to wait until next season to buy a new battery, so I tried one last time to get the bike started using a jump starter running 12v 10amps to the bike, but would only get the electric starter clicking. Thinking I could get it going quicker, I turned the jump starter to 100amps for a few seconds to start it and it still wouldn’t go. I tried again. While doing this, my gauges weren’t liking it and were coming on and off.

So I bought a new battery, and the bike immediately starts, but my speedometer doesn’t work and my “brake failure” light stays on while driving. I know both are associated with the speed/ABS sensors on the wheels. Thinking I may have bought a bad battery, I got another one. Same problem.

What I’m trying to figure out is if I need to replace the sensors or would this be an ECU problem. I’m sure I fried something being stupid with the jump starter.
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If the speedo stopped working, it’s associated with the rear ABS sensor.
It’s unusual to have such a failure arise from jump starting, so I can’t say whether it’s the sensor or the chassis computer. The front and rear sensors are the same part number, so if you could be bothered swapping them, this would isolate the problem - if the speedo starts working (and the ABS fault remains), then it’s the sensor.
The instruments cut out below a certain critical voltage so it isn’t unusual that they were ’doing their thing’ as you tried to jump start, just as the solenoid clicked in when you pressed the starter then out as the voltage dropped, the jump start connections not being able to supply adequate current, notwithstanding the capacity of the jumpstart battery.
1. Try disconnecting the battery for several minutes.
2. Try clearing any error codes in the ECU (if you have the tool).
3. Try “resetting“ the ECU (if the option exists) with the correct tool.
4. See what the tool says about the issues in question (can you see the CANbus display speed in real time while spinning the rear wheel but the display isn’t reflecting the same reading).

I don’t think your jump starter should have damaged anything. 100 amps is under what a motorcycle battery can generate, so not an overload…unless you connected incorrectly. I’ve jumped bikes with a car battery, by wiring in parallel, but I’ve never used a jump starter…so I don’t know what likely could go wrong.

Let us know how it works out.
I have now learned that I have power being drawn from my bike overnight. The battery will be completely dead within 10 hours.

I ended up taking the bike to a certified BMW mechanic, and he originally thought my ABS unit needed to be rebuilt. After further diagnosing, he says that it is the ZFE that needs to be replaced, and I have to take it to the dealer. I’ve looked into the cost, and it’s going to be over $900 just for the unit. I know that these units have to be properly coded by the dealer, but has anyone found a workaround to recoding a used unit or someone who can? Would rather not have to go to the dealer if I can avoid it.
I recall that some added electrical connections could trigger the ZFE in some bikes to stay powered on even with the key off. In my case, it was a Zumo GPS connected to the bikes OEM GPS connector (CANBUS) to supply power. I moved that to a direct connection to the battery, problem solved. Dealer blamed it on the Garmin GPS cradle's electronics.
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