98 V70 AWD General ABS Module Question

[rmmagow]

Sort of directed to Matty. The ABS/TRACS light goes on in my car every few days. In general I have only seen this happen during the summer months. Once the car has been shut down and restarted the lights go out and will sometimes stay out for a couple of days. It stays out during the winter months.
Is this the typical starting to fail mode for these things? I plan to take it out and have it repaired regardless, I'm just wondering if I should play with my sensors too. The other concern is that really the lights don't go on all that often and I'm worried it will check out as being OK when maybe it isn't. When the light is off, ABS does function correctly based on the vibration in the brake pedal on heavy braking.

[Fogducker]

https://www.matthewsvolvosite.com/forums ... hp?p=46827

[Matty Moo]

That sounds about right.

The heat doesn't have any bearing on the sensors, if it were something external it wouldn't be based on temperature or be random.

If I were to test it I probably wouldn't get any warning lights out of it either. Just reinstalling the harness will shift the pins enough to make constant contact for a little bit. I have yet to open a 96-98 module up and not see some degree of cracking on the pins.

[esl_97_850_T5]

What ABS trouble codes does it produce when the ABS light is on?

[rmmagow]

Beats me, no vida thing, just an OBD reader. It'd cost me the same to have them read as it would to have the unit resoldered. I'll give that a shot first and clean the sensors off too while checking wiring.

[Ozark Lee]

It'd cost me the same to have them read as it would to have the unit resoldered.

A wise decision from an experienced Volvo owner. There are only two kinds of '96-'00 Volvo 850/70 ABS modules - Those that have failed or those that are going to fail.

...Lee