97 850 GLT ABS/TRACS Problem

Can you help with my 1997 850 GLT Estate with only 87K Miles on the clock?
The ABS/TRACS light comes on very occasionally (6 times in the last 2000
miles) usually in hot temperatures. After the engine has been switched off
for 15 minutes or more the lights are out and everything is ok again for the
next few days. Can anyone please explain what the likely fault may be?
Thanks
John.

 

: Can you help with my 1997 850 GLT Estate with only 87K Miles on the clock?
: The ABS/TRACS light comes on very occasionally (6 times in the last 2000
: miles) usually in hot temperatures. After the engine has been switched off
: for 15 minutes or more the lights are out and everything is ok again for the
: next few days. Can anyone please explain what the likely fault may be?
: Thanks
: John.

Its very likely your ABS controller is dying. Do a google search on 850
abs and you will find plenty of info on this subject.

 

Most likely it's the ABS computer, it's a common problem. If you can
find someone to read the codes, you'll see you have a failure in the
right rear sensor. However the problem is with the circuitry inside the
ABS computer, not with your sensor.

Another, less common problem is the ignition switch, but this is
accompanied by inability to shift out of park without using the
shiftlock release button, and a few other things not working as well.

--
--
Mike F.
Thornhill (near Toronto), Ont.

NOTE: new address!!
Replace tt with t (twice!) and remove parentheses to email me directly.
(But I check the newsgroup more often than this email address.)

 

I seem to have a similar problem and am debating whether to let the
dealer replace it ($450 + labor) or remove it myself and have Vic Rocha
http://home.earthlink.net/~vicrocha/Volvo_Parts/Volvo_V70_ABS.htm
do a "repair and upgrade" ($130). Does anyone know whether either
of those options would get me newer firmware in the ABS computer?

Vic Rocha's site mentions heat buildup. That definitely does not seem
to be my problem. In fact, the only time the ABS and TRACS lights have
stayed off lately for more than a minute or two was after a seven-hour
trip. When I stopped for gas, they went out at 12 MPH and stayed out
until I got home. They promptly came on again the next day.

 

Heat buildup is one possibility, but I've seen this to be random. I had
to change the computer in my 98 S70 for this reason. Sometimes the
light would be on at startup, sometimes it would come on after a few
seconds, or minutes, or not at all. Fortunately for me I also have a 98
V70, a swap of computers moved the problem to the other car. Back when
I needed to do this I was not aware of any repair options. (The V70
still has it's original ABS computer, 6 1/2 years and 125 000 km, touch
wood!)

--
Mike F.
Thornhill (near Toronto), Ont.

NOTE: new address!!
Replace tt with t (twice!) and remove parentheses to email me directly.
(But I check the newsgroup more often than this email address.)

 

Funny, just today in my 94 850 Turbo Wagon the ABS and TRACS lights came on
for the first time. It was a hot day, near 100F. The lights stayed on
through several engine stops and starts. Later, after the temperature was
down in the 70's the lights were gone. My inclination is to not do anything
at all about it.

 

If I was you, I'd read the codes, write them down, clear them and then
wait for the lights to come on again.

--
Mike F.
Thornhill (near Toronto), Ont.

NOTE: new address!!
Replace tt with t (twice!) and remove parentheses to email me directly.
(But I check the newsgroup more often than this email address.)

 

http://home.earthlink.net/~vicrocha/Volvo_Parts/Volvo_ABS_feedback.htm

 

Thanks. I already contacted Victor and he said the pre-96 models didn't have
that problem, but that the 94's (mine) have a known ignition switch problem
that causes those lights to come on. But it seems strange to me that an
ignition switch problem would only occur on hot days.

 

It is just a matter of time. It seems that these units eventually have a
nearly 100% failure rate.

John

 

The codes for the ABS failure are often wrong. They often point people to a
"bad" wheel sensor where there is not a bad sensor. In this case you can
end up spending extra time and money going by the book.

John

 

After all the messages in this thread, I'm not sure what your "these units"
refer to...