Author [SOLVED] Random DTC error  (Read 738 times)

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  • Offline VVEGA   es

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    Offline VVEGA

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    • Bike: S1000XR 1st GEN
    • Town: Seville. Spain
    • Country: es
    [SOLVED] Random DTC error
    on: November 05, 2021, 07:43:56 pm
    November 05, 2021, 07:43:56 pm
    I am going to explain here the solution to a problem that I have found in my 1st gen s1000XR (2016). The issue has been a pain in the ass for several weeks till I found the problem. I hope it will be useful to the s1000xr community

    The issue: DTC warning light appears randomly, sometimes very frequently and others with several minutes between alarms. When DTC came active, the bike limits the rpm to around 4k rpm. As you can guess, it is very difficult to ride a motorbike with that random behaviour, and very dangerous also. The first time that I found that issue was after I washed the s1000XR with pressurized water, so I supposed that the issue came from some kind of moisture in connectors or shortcuts due to water somewhere. The day after the bike return to normal behaviour (without DTC issues) till several months later, after an annual service in the BMW dealer when the bike started to suffer from the same DTC issue (this time even worse).

    Using and OBDLINK interface and MOTOSCAN app, the MOT module(ECU) showed the following error:

    CODE: 21F730 (DME: ABS front wheel speed implausible)

    Checking the website www.bmwfault.codes, it said that the service plan was:

    Check wiring, wiring harness, and plug connections to ABS (CAN bus).
    Check wiring, wiring harness, and plug connections to ABS (direct connection).
    Check plug connector wiring harness to the DME.

    I proceed to disassembly the fairings, took out the EC, checked the connectors, and clean them,... and after assembly back everything the issue was still there.


    [SOLUTION]: Searching through the web, I found a similar error code, but in a BMW car
    . As you can see in the video (4:40), the guy resolved the problem using a washer as a spacer. That video gave me the path to resolve my problem. The BMW workshop manual says that the wheel speed sensor needs an air gap between 0.8-1.7mm (from the sensor to the sensor ring). Mine has 0.7, so I design a spacer to set the air gap in the middle of the range (1.25mm). After that, the bike runs like a charm, without any issue.


    I would like to post my problem so if any colleague finds the same issue it will be easy to solve. I haven't found the exact same issue on the web, so I guess it will be useful. As far as I know, all S1000XX models have the same wheel speed sensors, therefore the issue/solution can be applied to all of them.

    As I am not a native English speaker, please forgive me if I have not explained myself correctly.
    Last Edit: November 05, 2021, 07:47:32 pm by VVEGA

  • Offline Antares   gb

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    Offline Antares

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    Re: [SOLVED] Random DTC error
    Reply #1 on: November 05, 2021, 08:59:33 pm
    November 05, 2021, 08:59:33 pm
    Thanks for the write up, although this is a farily well known issue, first thing I checked when tyre shop knocked out my electronics was wheel speed sensors and ABS ring. They are super sensitive, even a little bend in them can give implausible readings and cause errors. All electronics depend on the wheel speed sensors, if either doesn't work you lose ABS, linked brakes, DTC, wheelie control and cruise control.

     



    dysfunctional