Today on my drivehome from work my "ABS" and "Tracks off" lights turned on simutaneously. Brakes work fine. What does this mean? The owner's manual tells me nothing

if its a earlier 850 you can check the error code. Mine did that too and it was the pedal positioning sensor that is located one the brake vacuum booster. there is a fix that one the member wrote up.
http://au.geocities.com/ozbrick850/abs-141142.html
I haven't actually attempted the fix as i just shook the connector area abit, reset the error code and so far so good. ken

Happened to my '97 850 T-5 at about 45k miles. It was under warranty (thankfully) and they tried a number of things, including cleaning/replacing sensors. Ended up with a new ABS module. Now at 85k with no futher problems.
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1997 850 T-5 (Chip, exhaust, suspension upgraded)

This happened to me recently. It turned out to be the computer module. Apparently the circuit board can develop cracks over time, not an entirely unknown problem if you read some of the posts on this site. It cost me just under $2000 Aust for the replacement job (labour included).

Please don't say you had this done in Sydney; I'll slash my wrists. If you're in the US, well, remember the exchange rate...also maybe Sweden is closer!

It was US. Now I'll have to look up the exchange rate.
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(98 S70 T5SE misc mods, mostly lighting) (92 940GLE)

Hi- I came upon this site because of the same problem! This is what I found-

"My 850 got stuck in park today, so husband told me to use shift lock button to get it out, it did come out but now my tracs off light and abs light is on. any clues? thanks kelly"

"The ABS/Tracks problem is not normally related to the shifter in itself BUT it's also possible that your cars electrical part of the ignition switch is failing and that could cause both problems together. If you move the key in the ignition switch (NOT engaging the starter with the engine running), does the ABS light go off or will the shift lock work by moving the key, then depressing the brake pedal? "

"yes, checked out volvospeed last night so this a.m. i tried the ignition shake with out starting and the lights went out. kelly "

"Easy fix www.volvospeed.com look under micro switch replacement..
something your husband.. can do in 1 hours.. save some big $$$$$$$$
some one even said buy the part at Radioshack for nothing... and it work the same... compair to dealer price....."

"Sounds like you need a shift lock solenoid microswitch, was a common problem for many years and it's not overly costly if you choose to have a dealer do it for you."

"Good. Volvospeed shows how to replace the switch. Have fun. You can get the parts at a good discount from Dan at volvoparts.com (or any number of other places). email or phone him."

"You need to pull the A3 codes and see what they say. Volvopeed.com, Ozbrick, a Motors or Haynes manual will show you how."

"Sounds like it may be the brake switch on the brake pedal or the electrical portion of the ignition switch. You may be able to wiggle the key in the ignition switch to see if that helps. If you push on the brake pedal and wiggle the ignition switch or slightly turn it (engine running) you may hear the Park interlock relay clicking on the passenger side and you may see the ABS light go off and on. Don't turn the key so far that you engage the starter.

Volvo has problems with the abs control units on this car and 850s. I would take it in to the dealer to have it tested."

my model year is 96, but it has a manual tranny, so the micro switch/shift lock does not apply. The lights go on after driving for a while...meaning they aren't illuminated upon starting the car, so i don't know if its a problem with the computer. The lights go off If i turn the car off then on again. couldit be the abs sensors?

It is most likely the ABS/TRACS controller. There's a write up on the volvospeed site; here's the link: http://www.volvospeed.com/Volvospeed.htm (select "Repairs/Maintenance," click the picture to enter "Bay13", click on "Brakes & Wheels.").
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(98 S70 T5SE misc mods, mostly lighting) (92 940GLE)

one thing that i wanted to ask...on bay13, it says that there is a weak crimping just under the fusebox. i have a 96 so i guess this is a possible cause for my abs/tracs problem. is it literally under the box? how do i take off the box? and with all the wires down there, how do i identify the wire that need to be soldered?
thanks for any help/clarification

My 96 850 has this problem. Took it to the dealer, pulled the codes from the computer - right rear brake showing problems. They cleaned the sensor on that brake, and as I was driving it home, the light came on again.

Had the dealer look at it again today as I was getting new front rotors / pads. They want an excess of $750 CDN for a new abs/tracs "brain".

I know abs is a very important safety feature, but thats a big price tag for something that I deem Volvo SHOULD have recalled, since it is such a vital part. (As it is obvious this is a problem with the 850 series).

I've heard there is a solution of new wiring or something, but the dealer mentioned nothing about that. I've also heard someone resoldering the connections to the abs unit.

Just my story..