Hey guys, spent a good day saturday out wheeling and having fun, and at somepoint during that, my ABS light came on and stayed on. On sunday the light remained on through the day and 2 or 3 times while driving the ABS light cleared itself off and immediately after the ABS pump started going on its own(I could hear it) even though I had no foot on the brake! It did activate while applying the brakes on one occasion and I almost sailed right through a stopsign.

I got in to work today and did the ol' flash code trick and go a "2-8" which translates to "no voltage to abs solenoid valves, faulty valve relay or wiring". I've gone through and verified voltage at the ABS module fuse, the under dash fuse, and at the relay beneath the glove box(is this the valve relay?) and swapped that relay around with another known good unit and it made no difference.

I also connected an autologic scanner to the vehicle and its kicking back with a lack of communication issues. The autologic cant talk to the ABS control module and asks to verify that everything is powered up correctly/turned on.

Where should I begin looking next? Common wire break somewhere that could cause this? Where is the valve relay?

Thanks in advance

 

Pull the #6 30 amp fuse for the ABS pump under the hood and be done with it. At least that's what I have always understood as the best fix for the ABS on the D1s due to the general unreliability of the system.

 

No... I'm very much an advocate for fixing things the right way, but thanks for the advice.

I've been spending time chasing wiring after work the past week and will update if I find the issue. I am thinking it may be a bad ground in the foot well or bad connection to the data link

 

The first reply you received is the general consensus. However, if you have the inclination and the finances then you might as well replace all the ABS parts as they are all pretty old.

That said, even new and fully functioning these were not the most reliable systems and you still may find yourself sailing through a stop sign or worse.

 

Replace all parts in a system because of fault? lol do we replace engines when they have a misfire as well? ABS is not witchcraft, and while the rudimentary OBD make it not as simple to diagnose and work through, this old school system is simpler and has less parts to fail than a D2 with full TC and other electrical nannies involved.

I'll report back when the issue is resolved

 

you have one fault now in a system that is close to 20 years old. maybe the previous owners maintained the ABS, maybe they didn't. the ABS on these trucks is known to be quirky at best and dangerous at worst even when in tip top shape. now there's a phrase i didn't think i'd ever use, tip top shape. i'm not even that old.

but fix it. report back. maybe you will find a way to keep the system working, effective and safe that will benefit the forum and other D1 owners.

and for the record, i do keep the ABS, Traction Control and Hill Descent functioning on both my D2s. they are reliable and safe braking systems that are not difficult to maintain.

 

Yeah the ABS in these is useless.

 

Even without a diagnostic tool. If your having comm problems it might be the ABS ECU itself. Mine failed for ECU internal fault (according to the blink code), replaced it with one inexpensively purchased from Paul Grant. Besides that it only wigged out over wheel sensor gap too large which is easy. My ABS worked with over 200k and spent 8 years as a daily. Usually the most common issue is wheel sensor gap too large.