I'm experiencing the intermittent ABS Tracs Light
coming on. Doesn't seem to be the ignition key.
Am considering replacing the controller board as
recommended. Is this something I can do myself?
I have been warned off by Voluparts & IPD but hate
to got to the dealer and get ripped off. If doable
who would be good to purchase the module from? I'd
only consider a new unit not used because of the
chronic problems.
Thanks,

John
96 850 Turbo

Just as a point of clarity, the ABS ECU is fastened with four external Torx screws (T6 if I recall correctly) and should be no problem to remove. I disassembled mine and resoldered the connector joints; it has been working fine ever since. If you purchase a replacement the swap should take 15-20 minutes.
--
Ron

This is the one item guaranteed to fail eventually, it seems, in every 850 / 70. About time the feds made Volvo fix this once and for all.

The abs/tracs controller is a pc board under the abs block in the engine compartment (what a stoopid place to put this card) where temperature changes and directly-above-the-axle bounces conspire to create micro cracks in the soldered connections. (If you have a solder reflow tank, great! Otherwise, be prepared to part with $300-400 just for the part alone.)
--
(98 S70 T5SE misc mods, mostly lighting) (92 940GLE)

This has happened to a lot of 850 owners, basically, it's the ABS/TRAC controller that may be bad. Or, some people have found faults in the ABS sensor, which is located in each wheel. If it's the former, the controller is a black plastic box attached to your ABS pump. Removing it can be a pain because it is attached by six very small hex-head screw that may be corroded by rust. If so, it could strip easily.

However, since your controller may be dead anyhow you can just hack it off if the screws become stripped. You can obtain a replacement unit for ~$400 mailorder, or try to find a used one through a junkyard parts service on the web.
I've changed my ABS/Trac controller and the problem is gone.

Best,

Peter
96 850R
02 Vette Z06

i had the light go on once, and i decided to ask my dealer about it. Apparentyl on the 96 850's and only them, there is a bulletin regarding the light abs and tracs light coming on. SOme major rewiring deal they have to do. The dealer told me i probably couldnt do it myself. Somehow i suspect he wanted to make the 2 hours of labor off me. I did see the bulletin in his book however, and it was like 5 or 6 pages so who knows. My light never went back on again, so knock on wood.

The dealer did say that there was a wiring harness that i would need, to replace. If anyone knows what the service bulletin actually recalls, IE what the real problem it addresses is, i would like to know.

Hey KenK,
The bulletin refers to a soldering problem in the left and right sensors. The repair is to remove the bad solders and splice and solder new joints. The dealer wants to charge two hours because that is what Volvo warrantee pays. Now if you want to do the job yourself, go ahead. I have done lots and got fairly fast at it and it still takes a good 1 1/2 hours. Want a race??
Gazzer

Since I had my repair done 'by the book,' does that mean it won't fail again on my drive (heh, heh) to a quarter million miles?
--
(98 S70 T5SE misc mods, mostly lighting, red calipers) (92 940GLE)

I would also like to see this "service bulletin". The dealer said my 96 850 requires a whole new abs/tracs unit.. but they never said anything about it needing rewiring instead.

So do I understand this discussion to say that Volvo will perform the
soldering/rewiring at no cost to the owner? Is it standard to do that
when there is not a formal recall?

Please clarify,as I have had this problem for a year.

Thanks,

Cliff Karchmer

Did you ever hear anything about Volvo replacing or repairing the ABS Control Unit? Maybe this is just for the 1996 model year.
--
1990 744Ti and 1998 S70

Hey Zea,
Open your hood and lift the fuse panel cover. If you have green dot your car has been updated. If the abs codes point to front sensors, this repair may help.
Gazzer