No ABS - What happened???

headly · Post by **headly** » 12 Jan 2011, 20:00

Hey everybody. New to the site and so far very impressed. Just (6 weeks ago) purchased a 1998 V70 GLT and am very happy with it. Have always had a thing for Volvos. My second car at 19yrs old was a fantastic 1970 1800e. Anyways at the first snowfall here in southern Ontario, Canada the ABS and TRACS seemed to work fine in that the pedal pulsing and brake control seemed to be working. This is even though my TRACS light on the switch does not work or the dash lights for the ABS and TRACS don't work even on start up. Now on the second more significant snow fall the ABS and TRACS seem to not be working at all. As well, as I remember back I recently (in the last couple of weeks) don't remember the pulsing sound happening as the ABS system did its self check (at about 15~20km/h) but it did work initially. Any ideas as to what might have happened to my ABS and are the ABS and TRACS systems linked directly? I have read about the ABS module and that sounds like a plausible idea and if so can I get more detail? I am somewhat mechanically competent but am much better with explicit instructions. Thanks in advance for the help...

Post by **jimmy57** » 12 Jan 2011, 20:24

OK, I'm suspicious that the bulbs are removed and you have an ABS module problem. The cracked solder joints on ABS module circuit board that is the most common malady will let ABS work intermittently. The ABS may work for quite a while and when you drive through traffic and underhood temps get higher the ABS circuit board loses a connection and then it shuts down.
The ABS and TRACS lamps should be on until you start engine. If I remember correctly they are default on lamps turned on by inst cluster and a signal from ABS module is needed to turn off the lamps.
BTW, the TRACS is a function of the ABS module, no other control unit for that feature.
The module is not the worst job you'll ever do but the torx bolt heads are a little tedious to navigate.
There is a lot of threads on here for ABS module and for access to dash warning light bulbs.

headly · Post by **headly** » 12 Jan 2011, 20:36

Thanks for the reply. I thought from all that I've read here that it was most likely the module and I'm assuming the bulbs have been removed or burnt out. Is there any way to check and see if it is the module for sure? Any simple test? And I did see at one point a place that you can send the module for a rebuild. Can you/anybody guide me to that place or is it a simple DIY repair? I have a soldering iron but have hack skills at best with it. Thanks again...

Post by **jblackburn** » 12 Jan 2011, 20:58

Here is the DIY repair which bascially just involves removing the module and fixing cracked solder joints:
https://www.matthewsvolvosite.com/2007/1 ... le-repair/

Or contact forum member Matty Moo (just search him; you're bound to stumble across one of his posts) who rebuilds them for $60 or so I believe.

To know for sure, I suppose you could have the codes read - more expensive than removing the module & having it sent off. I don't know how to tell without the lights being on, but it is one of those items that has failed or will fail on just about every one of these cars.