ABS Power modification

Discussion in 'GS Boxers' started by Leebo, Aug 23, 2010.

  1. switch

    switch Romanian Trailbiker

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    Allright, I've done about a hundred miles with my the modded ABS and I dare say it worked flawlessly.


    Here's what I did (on a BMW R1100GS, prod yr 1997):
    1. Remove seats, fairing (GS only has like one piece) and fuel tank
    Tip: If you have a tall chair available, put it on the right side of the bike, next to the rider footpeg. You can rest the tank on the chair to avoid having to disconnect the fuel lines. Be extra careful in securing the tank!
    2. Disconnect battery terminals -- for the sake of the bike's electronics

    3. Locate and disconnect the ABS connector: it's a large connector going into the the left side of the ABS unit just in front of the battery
    TIP: the connector is held in place by a latch on the bottom end. A flat screwdriver can be used to release the connector's bottom clamp. Hard to explain, even I don't get it after doing it twice. Bottom line is that you don't need to undo anything else, just push the clamp out of the way and unplug the bottom end of the connector. Top end just wiggles out.

    4. Locate and pull out the wiring harness splice point #15: it's behind the alternator, left side.
    TIP: The splice point is likely hidden behind the rest of the harness when you look at the bike from the left side. Here's some pics, courtesy of a guy that did a similar mod on his R1100:

    [​IMG]
    5. Remove the insulation and find the large bundle of 9 green wires. Cut the crimping and isolate each of the wires

    [​IMG]

    [​IMG]

    6. Locate pin #15 on the ABS connector
    TIP: When looking at the abs connector pins with the wires coming out the bottom, pin #15 is on the right row, second pin from the bottom up

    [​IMG]

    7. Determine which of the 9 wires from the bundle connects to pin #15 on the ABS connector
    TIP: Only one of the 9 green wires in the bundle connects to pin #15. It's one of the THIN wires. MARK IT.

    TIP: After identifying the wire, mark it (did you mark it yet?) and reconnect the ABS connector -- you're done with it.
    8. Bundle the 8 wires not connected to pin #15 and solder them back together. Take extra care to make sure they are ALL soldered together properly.

    9. Solder the wire going to pin 15 to your 5-inch piece of wire; isolate all solder points, check integrity then run your wire out of the bundle and tape the bundle back together
    TIP: Don't push the bundle back in yet!

    TIP: In the picture, the wire is brown (indicated by the RED arrow), despite the fact that it's not a BMW standard ground wire.

    TIP: The BLUE arrow indicated the wire coming from the alternator's D+ connector.
    [​IMG]

    10. On the rear-left side of the alternator, locate and remove the D+ connector with the BLUE wire
    TIP: In the picture above, the blue wire is indicated by the BLUE arrow.

    11. Splice into the blue wire and solder the other end of the 5 inch wire you connected into the bundle (step 9). Carefully isolate everything after soldering.
    TIP: At this point, the electrical diagram for the ABS has been modified to:
    [​IMG]
    12. Test everything (you DID re-connect the ABS connector and alternator D+ terminal, right?). If it appears ok, isolate everything nice and tight, and reassemble the bike. Prepare for a test-ride.
    TIP: The ABS lights will behave differently during startup! This is expected and suggests you did things right.

    That's it. Test ride and slam the brakes to check for abs functionality.

    Now, during start-up, the ABS lights work differently:
    - when you turn the ignition, the top ABS light comes on solid
    - during tick-over, I *think* the top ABS light goes out -- didn't pay attention, sorry
    - after the engine starts and the battery light goes out, both ABS light blink in unison (indicating the ABS is initialized).

    That's the only difference. Note that disabling the ABS requires you to keep the ABS button down until the engine starts AND the battery light goes out.


    EDIT (one year later): I've done about 7k miles with this ABS mod. No issues, never had the ABS fault.
    #21
  2. usmanet

    usmanet Adventurer

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    The instruction is it for R1100GS or R1150GS !!:D
    #22
  3. switch

    switch Romanian Trailbiker

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    It was done on a '97 R1100GS BMW. Remembering a 1150 I saw a while ago, I'd dare say it's the same thing.
    #23
  4. Poolside

    Poolside Syndicated

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    <BR>
    The ABS power bypass works for both the 1100 and 1150.

    <BR>
    #24
  5. usmanet

    usmanet Adventurer

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    Hi Switch,

    For point 10 on your instruction i can't find the BLUE wire that located at rear-left side of the alternator and the D+ connector. Can you take the picture of the D+ connector and the rear-left side of the alternator wire.

    Many Thanks for the help.. Cheers
    #25
  6. switch

    switch Romanian Trailbiker

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    I spend 15 minutes on that one. There's three wires coming out of the alternator: two THICK ones (bundled up) and a thin one. Sadly, with the bike assembled I can't take a picture of the alternator.

    Imagine looking at the alternator from behind. You'll see a pair of thick red wires coming out at approx 11 o'clock and a single, thin blue (might be very dirty blue!) wire coming out at about 10 o'clock. It's a bit hidden, about where the wiring harness splice point (see first picture in my previous post) is tucked in behind the rest of the harness.

    Basically the D+ is a single black terminal with a short blue wire that is connected to the rear-left side of the alternator, some half-an-inch below the two thick red wires. If you can't find it, simply feel for it on the rear left side of the alternator.

    If you DO find it, we'd all appreciate a picture.


    EDIT: Whoa, one of the pictures previously posted shows the blue wire. I've updated the pic and tutorial (check out the blue arrow):
    [​IMG]
    #26
  7. usmanet

    usmanet Adventurer

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    Hi Switch,

    Just wonder whether after the ABS Power modification done on the bike, the ABS reset that on the Hall Of Wisdom can be follow or working if the ABS is need to reset. Can you confirm on this. :wink:

    Many Thanks.
    ==========
    #27
  8. switch

    switch Romanian Trailbiker

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    The ABS reset must be done with both lights blinking in unison. After the mod, you need to start the engine and rev it once (if you have a low battery), THEN do the ABS reset thingie.

    Also, disabling the ABS means holding the ABS button from key-on throughout cranking, until you rev the engine slightly and the battery light goes out.

    Actually, I'm not sure if you need to hold it from key-on -- might work if you just press it before cranking.

    ...sucks if you don't have a neutral sensor :D
    #28
  9. Dan Cãta

    Dan Cãta Long timer

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    The abs on a 1100 can also be disabled if the bike is off, you keep the green starter button pressed, switch ignition key on, the bike starts, then release the green button :)
    #29
  10. toecutta

    toecutta 06 R1200GS Adventure

    Joined:
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    Hi All

    Finally just got around to doing this to remove the "multistart ABS" my 96 GS has.... errr... had

    I just created a piggyback blade connector off the blue charge wire from the alternator
    found pin 15 of the ABS connector (after 1st eying off the motronic connector in error)
    as my wiring loom is starting to disintegrate my access was a little easier
    combination of spade connectors, solder and heat-shrink made the connections
    used some spirax and some more heat-shrink to armor it all up again

    MUCH simpler than the relay solution... 20 mins in total... should of done this YEARS ago, would of saved a HEAP of wear and tear on the starter cct

    worked 1st time... works a treat

    thanks heaps

    toecutta
    #30
  11. bdarling

    bdarling Weatherman

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    Hint:
    Follow that blue wire forward and you will find a tidy way of tapping the D+ circuit. That blue wire has a ring terminator on the alternator side that is held to a post by a nut. simply remove the nut and secure your new pin 15 wire to the post over your blue wire.

    -B
    #31
  12. toecutta

    toecutta 06 R1200GS Adventure

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    Folks... FYI

    I had my old girl in for a clutch transplant last week (169,000kms out of the original) everything went smooth except i gave the authorised BMW dealership heartburn when they put it all back together and didnt get the ABS flashing lamp startup they were expecting. they checked the service history and noted the last visit (6 months ago) they COULD read the ABS diagnostics... they thought that they had fried the bikes brain

    After telling them over the phone about the mod, they still felt confused. I picked the bike up from them as i needed it back for transport and the ABS light sequence was just wrong (top lamp on all the time). I went home, unplugged the link to the alternator, and jumpered in the battery. Then i did the ABS reset as per the Hall of Wisdom. Turn the key, the lamps behaved as i expected... start the engine, 2 lamps in unison, start moving, 3km / hr ka-chunka.. ABS engaged and operational (verified with an attempted rear wheel lock up)

    With this mod... Because the ABS unit doesnt get power until after the engine is spinning, diagnostics could not be run nor be reset. Rather than think about what they were seeing they relied 100% on their diagnostic tools results and not what was happening in front of them

    i do feel a "little" guilty about this... and "not" at the same time (101 of basic electronics fault finding asks... has it got power Y/N.. if N.. then why not?).. regardless, when / if you drop your post modified bike to the shop... might be a good idea to tell them, or better still, as I have done, wire in a "service switch" (switch between the alternator and the battery for the 12V feed back to the ABS brain)

    This might help to keep your relationship with the dealership rosy :D

    cheers

    toecutta

    PS.. their work on the clutch / bearings / seals etc during the transplant was BRILLIANT
    I recommend Procycles St Peters
    #32
  13. keithbob

    keithbob Adventurer

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    Just finished doing the no-relay ABS mod and it was SO NICE to just start the bike form cold and have the ABS working right off the bat. Thanks all who developed and refined this!

    My method was to cut the green #15 just above the connector pin and solder in to that, then run the wire to the blue terminal at the alternator. I didn't want to screw around with the big 9-wire gang connection and then have to put eight of them back together. I slid the wire in through the rubber sleeve and up into the connector housing, using liquid-tape and a generous length of shrink-wrap to protect the solder joint.
    #33
  14. ElMartillo

    ElMartillo I See Faces...

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    Just completed the no relay mod while changing the alt belt on my Y2K 1150GS. I chose to seperate and extend the single green from the 9-wire bundle. Unfortunately I can't test run the bike yet, as I was given an incorrect belt by the dealer. The upper ABS light comes on solid when I turn on the ignition, so I'm confident I performed the procedure correctly. Just thought I'd mention a difference on my bike that I hadn't seen mentioned earlier: My alternator has 2 blue wires coming off it, with a spade-type connector.

    Thanks for the simplified mod and the photos!

    Cheers! :thumb
    #34
  15. slartidbartfast

    slartidbartfast Love those blue pipes

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    Completed the same mod while I had the tank off to replace the fuel filter. Cut the green wire and crimped in a male and female spade connector (so in the unlikely even I ever want to put it back to stock, it'll be as simple as swapping the plug over. I had to add no extra wire (although it was easier for me because the rubber sheath over that part of the harness has conveniently rotted completely off.) I taped up the male spade safely out of the way and plugged the end of the green wire that goes to the ABS "brain" onto the alternator terminal using a double-spade adapter and it works as advertised. No more ABS faults.
    [​IMG]
    #35
  16. DirtDagger

    DirtDagger Adventurer

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    Is there only 1 or 2 green wires running through that bundle? If more that one how did you determine which one it was? Thanks
    #36
  17. slartidbartfast

    slartidbartfast Love those blue pipes

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    Pretty sure there was only one that color green. I did split the plug to check which pin it went to just to be sure.
    #37
  18. DirtDagger

    DirtDagger Adventurer

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    Okay great. I'll test the circuit to be sure. Thanks
    #38