What is this part- 1990 TBI setup.

Discussion in 'Engine Topic' started by Eric, Oct 26, 2006.

  1. Eric

    Eric Veteran Member Lifetime Gold Member

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    Been collecting TBI parts here and there and came across [most] of a system in a 1990 GMC 2500 pickup today- I got what I didn't have already- but there was a part I hadn't seen before connected to the wiring harness.

    It looks like a shrunken ECM- encased in plastic but attached to brackets on the outer side of the master cylinder. It had two electrical connectors of -give or take- 6 wires each.

    Any idea what this thing is? I've never seen anything on it in manuals or on the web that I've looked at.
     
  2. tom3

    tom3 Veteran Member

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    I'd guess that's the antilock brake control. Lot of these trucks had rear only antilock to keep the back end from sliding around and had a control box there. Black box about one inch think, maybe six inches long.
     
  3. Eric

    Eric Veteran Member Lifetime Gold Member

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    That was about the size of it, 6" long x 1" thick x 4" high. Anti-lock brakes on rear only? In a 1990 truck? Seems kinda funky.
     
  4. Damon

    Damon Veteran Member

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    No, it's for real. My 1990 454SS pickup has the same thing. Definitely rear ABS only- and that's the computer that controls it.
     
  5. busterswt

    busterswt Veteran Member Lifetime Gold Member

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    Rear ABS control box. Caused my 1990 brake light to blink for years. Usually kept the box unplugged to keep the brake light off.
     
  6. patgizz

    patgizz Moderator Lifetime Gold Member

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    ABS brain. yup rear only, not a fan. on my 92 i stripped the damn pump putting a new line in, and deleted it altogether.
     
  7. hhott71

    hhott71 R.I.P 11/19/18 Lifetime Gold Member

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    That is what it is.
     
  8. Brian79Z

    Brian79Z Veteran Member Gold Member

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    In this year, it was the RWAL system (rear wheel anti lock) early truck antilock systems only had it in the rear. Cars had 4WAL (4 wheel anti lock)
     
  9. Eric

    Eric Veteran Member Lifetime Gold Member

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    Yup- learn something new (and weird) every day...


    Thanks for the help. Guess I won't be going back to get that part. :)
     

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