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ABS swap - mecatronic to bosch

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  • ABS swap - mecatronic to bosch

    ****UPDATE 3****
    Wiring is all set, battery is no longer draining. However i have to pull everything back out, because one of my lines is leaking... oh the fun
    THe wiring schematic below has been updated to show the proper wiring

    ****UPDATE 2****
    BuckeyeSVT over on the forum took a look at my wiring and noticed a couple of issues... I fixed the wiring last night, but have yet to test it. I will update probably tomorrow.

    Looks like the Bosch unit is slowly draining my battery... As long as the car is started once a day, i think it will be fine, but i have a truck, car and motorcycle so it doesn't get started daily... Im pretty sure i can fix this with a relay, but im gonna go back through the wiring to see whats going on. I know its definitely the ABS unit because when the battery was almost dead i heard a ticking in the engine compartment and when i unplugged the connector, the ticking stopped.


    So after following a few threads specifically and grabing the Ford Repair CD, which was invaluable for the wiring schematics.
    I headed to the junk yard to grab a bosch unit with the lines and plug.
    My donor was a 2000 se contour, it was much easier to get the unit out of the 4 cylinder than it is the 6.

    Steps to replace the abs unit.
    1) Disconnect negative battery
    2) Remove air intake
    3) remove master cylinder
    4) Remove brake booster - this was a pain in the butt.
    There is a clip on the brake pedal that holds the rod from the booster. Also you need to remove the booster from its bracket. There are 4 nuts that hold the booster to the bracket and 4 nuts that hold the bracket to the inside of the firewall. I removed the nuts for the booster, so that i could get some room to remove the booster from the bracket, then i pulled the booster and then the bracket.
    5) Disconnect the brake lines
    6) Removing the mecatronic unit is a pain, i seperated mine from the mount then removed the mount. The mount is 4 bolts. The abs unit has a set screw on the engine side the once removed, the unit can be twisted out.
    7) Went to the junkyard and got the unit, the connector (with 6 inches of cable) the mount and the brake lines.
    8) Put it all in. Everything is pretty straightforward, you have to splice to the connector into the old wiring, below is how i did that.

    Note... there is a earth ground wire under the bootom bolt of the bracket that holds the abs unit. When i took the bracket out, the ground wire was laying down, it had been disconnected on the other end. I couldnt find where it went, and after hours of searching said screw it. Thankfully everything works fine, not sure if this will cause issues or not.

    From BuckeyeSVT over on

    New connector wiring
    Pin #1 : Empty
    Pin #2 : RR+ Speed Input - Old Pin #9
    Pin #3 : RR- Speed Input - Old Pin #10
    Pin #4 : RF+ Speed Input - Old Pin #7
    Pin #5 : RF- Speed Input - Old Pin #8
    Pin #6 : Stoplamp circuit (Must run wire to stoplight switch (Orange/Yellow) wire).
    Pin #7 : Not Used
    Pin #8 : F7 BJB 10A Power Input - Old Pin #5
    Pin #9 : Not Used
    Pin #10 : Not Used
    Pin #11 : Not Used
    Pin #12 : Ground - Old Pin #1
    Pin #13 : Power 12V (Shared with Pin 14) - Old Pin #3
    Pin #14 : Power 12V (Shared with Pin 13) from 60A F3 BJB - Old Pin #3
    Pin #15 : Ground - Old Pin #2
    Pin #16 : BK/BU Park Brake/Low Fluid Level ground input (Optional)
    Pin #17 : Not Used unless equipped with Traction Assist
    Pin #18 : Not Used unless equipped with Traction Assist
    Pin #19 : Not Used
    Pin #20 : LF+ Speed Input - Old Pin #21
    Pin #21 : LF- Speed Input - Old Pin #22
    Pin #22 : LR+ Speed Input - Old Pin #23
    Pin #23 : LR- Speed Input - Old Pin #24
    Pin #24 : DLC ( Direct to DLC - No PCM) - Old Pin #11
    Pin #25 : ABS Indicator (With older cluster will cause ABS light to stay on permanently) - Old Pin #20 if you want an idiot light on all the time.
    Pin #26 : Not Used
    Pin #27 : Not Used
    Pin #28 : Not Used
    Pin #29 : DLC - Through PCM - Can't be used with 1998 RJL1 PCM
    Pin #30 : DLC - Through PCM - Can't be used with 1998 RJL1 PCM

    Any questions please feel free to ask, as this is very fresh in my head.

    Anyway when i buttoned it all back up, i took it out. Brakes are a bit squishy, i will have to rebleed tonight, other than that ABS is working like a champ. Thankfully we had a lot of snow and ice yesterday, so the roads where also covered in sand so it was really easy to test the abs capabilities.

    Next i need to disconnect the ABS light, as i wont be able to get a sticker with it on.

    Gordon Matthews

  • #2
    Great write up. Glad you got it going!
    Pearl Black 98 CSVT- Konis GC l OZ Supperleggeras l B&M l Port-Matched 3l SVT Cams w/gutted SVT LIM l EH SVT UIM l 65mm TB l NPG CAI l COPs l Black Hightowers w/projectors l Pre98 l Freedom Design FSTB l RSTB l
    2kBlack/Tan CSVT 77k Restore
    3 CSVT Sold


    • #3
      Dom can sure do good work.
      98 SilverFrost SVT- '04 3L Hybrid built by Buckeye SVT's Stage3Motorworks
      Terry Haines built trans. w/ Quaife LSD, updated shift forks, tower mod, Modded just ask!
      You just made Baby Jesus Cry-Dominic (Mods)


      • #4
        power issues... update posted to original post


        • #5
          Ok so I am in the process of doing this and have some issues. I saw the above write up on the ABS swap and had some questions for you. Hopefully someone can remember some things. My questions are towards the wiring. I am looking at the pin diagram and you stated that Pin #16 : BK/BU Park Brake/Low Fluid Level ground input (Optional). My question is do you hook this up and if so where do you connect it. I was looking at the factory schematic and was wondering if it could be hooked to the small BK/Ye wire that is pin # 19 on the old connector/abs unit. Also has anyone hook up Pin #25 that is the one if connected it would cause the ABS light to stay on. Also how easy was it to bleed the system after everything was connected.


          • #6
            Anyone know if this mod effects the cruise control? It seem like ever since doing the ABS pump upgrade, my cruise no longer works! Any suggestions?


            • #7
              I wouldn't think so unless you removed the cc unit and didn't install it back in correctly. otherwise the only thing that I might guess is related is the stop lamp circuit as I am not sure exactly how the cc unit knows when the brake is applied so it shuts off.
              - 12 Focus SE
              - 99 Contour SeVT <- 3L/NPG Turbo
              - 2k Contour SVT - #2137


              • #8
                the CC unit takes it signal from the brake switch directly on the pedal.
                TZT Performance
                officially a troll. '93 3000GT VR4 #2229/2595

                '00 Black SVTC - sold 5/1/10
                '97 GL Turbo Zetec - gone