abs lite on
Post Fiend
Joined: Jan 2005
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there was a thread here a few weeks ago on pulling the RABS codes, if you do an advanced search you may find it.
There should be a black wire with an orange stripe behind the glovebox, disconnect it from the black wire and with the light on ground the wire. The light should start to flash the error codes.
However as both lights are on together I would say to check the brake fluid level and also the wiring connector at the master cylinder for corrosion/loose. It is also possible you have a bad fluid level sensor.
Hopefully some of the experts will chime in soon.
There should be a black wire with an orange stripe behind the glovebox, disconnect it from the black wire and with the light on ground the wire. The light should start to flash the error codes.
However as both lights are on together I would say to check the brake fluid level and also the wiring connector at the master cylinder for corrosion/loose. It is also possible you have a bad fluid level sensor.
Hopefully some of the experts will chime in soon.
Post Fiend
Joined: Jan 2005
Posts: 8,402
Likes: 10
According to my list code 4 is "open/grounded valve reset circuit". Also something I did not know, it is the only fault that throws a code that will turn on both lights.
Have a look at the wiring plug connector at the RABS module (on inside of left side frame rail). Check that there is no corrosion and that it is tight.
Have a look at the wiring plug connector at the RABS module (on inside of left side frame rail). Check that there is no corrosion and that it is tight.
Post Fiend
Joined: Jan 2005
Posts: 8,402
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It was a long shot at best. One other thing you could try (another long shot) is to flush new brake fluid through the rear brakes and clear the code and see if that helps.
Failing that the only solution may be to replace the RABS module but that is quite a lot of $ to spend without certainty of a fix.
Failing that the only solution may be to replace the RABS module but that is quite a lot of $ to spend without certainty of a fix.
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Lead Driver
Joined: Feb 2002
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From: Greater Austin, Texas
IMO the RABS on these trucks is dangerous and worse than having nothing at all. I have had 3 of this vintage and a 2000 SuperDuty that was in the same boat, I always pull the ABS fuse and also the ABS warning bulb and go on down the road.
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Post Fiend
Joined: Jan 2005
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There a couple of ways to clear the code. If I remember right (and I may not) if instead of grounding the diagnostic wire (the one that starts the code sequence) you momentarily ground the other one the codes will be erased.
Second if you lift the negative battery terminal off for 5secs the codes will be erased. If you have a security coded radio it will loose its code also doing this.
Second if you lift the negative battery terminal off for 5secs the codes will be erased. If you have a security coded radio it will loose its code also doing this.
Post Fiend
Joined: Jan 2005
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You can correct me if I`m wrong but you are correct for RABS1 but I think RABS2 does store codes.
Right? Wrong?
Posting Guru
Joined: Sep 2008
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From: Baltimore
If my rig sits overnite in damp weather, the first time or two I hit the brakes, the rear locks up. Also, sometimes during normal dry weather stops, the ABS will activate. I don't like rear ABS and am also thinking of doing away with it.
New User
Joined: Jan 2006
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Here's a little thing that happens to me every time I do brake work on my 92. The floats inside the master cylinder reservoir get stuck down. Have you tried pulling them up manually? I use a set of needle nose pliers or even a pencil if pliers aren't available.
Good luck.
Good luck.