So I have an issue with these lights coming on and going off. It'll stay on for a while and then off for a while. Today I had autozone read the codes and all of the solenoids and such seem to be present on the list (all the valves and such for all 4 wheels). Oh joy... So basically before I buy a new (likely already rebuilt) CAB or send it for a rebuild I just want to know what I should look at. Like a relay or fuse issue.

Thanks in advance.

 

Well I believe I solved the problem. I can't recommend doing this but I had nothing to lose... I narrowed the issue down to being in the ABS module itself, and decided since I have to replace it anyway why not have a look inside and see. When I got it apart (getting it apart was a huge PITA) I found a loose capacitor on the board, so I soldered it on. I thought I might have knocked it loose myself, and I may have, but I fixed it either way. I also noticed the thermal grease was old and dry so I put some fresh stuff in there. Its now working fine and the light is staying off.

 

that's weird that it just came off

 

I read around various things on the internet and apparently Volvos are the most prone to this kind of thing. Basically what happens is the heat and vibration can loosen things, I've seen it happen in vacuum cleaners and other appliances and electronics too.

 

I've seen capacitors explode before, but not fall off. I suppose it is possible after years of bumps and shocks though.

 

I have that problem with my truck every now and then, could be the problem. Usually I just restart it and it doesn't come on again.