Trying to troubleshoot this on my son's car, about to yank the module and get a rebuild, butthought I would ask here first. Other things to check first? Is there a good ABS Module thread somewhere? Should we check/clean the wheel sensors first? Seems to me that if the ABS/TRACS comes on without moving the car it shouldn't be them. I have an OBD code reader, haven't hooked it up yet.

Is there a way to use the MFA/dash to read off codes?

Thanks for any advice. The rebuilt modules are pretty cheap but I just want to know if there are other things to check first.

JH

 

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Anyone??

 

Hi there have had Volvos for past three years now the last was a 850 t5 that had a serious abs/tracs problem first thing in the morning i would go off to work and the abs pump would start wurring then the abs light would come on but sometimes it would be fine untill i came to restart and then it would do the same thing again changed all sensors trying to find the problem but failed even changed the driveshaft ends because they seemed to be a bit scabbie but still no joy. My Friend at volvo Shrewsbury plugged it in for me and still could not find a problem with it but one of the mechanics advised me that the abs module was at fault and he was right bought one off ebay for 60 pounds and was laughing. So would advise checking all sensors and connections making sure they are making good contact. Rear ones are vey delicate so be careful make sure that the abs rings are clean from brake dust and they have all their teeth, the front ones the same but must not be too corroded as the sensors will not be able to readthe gaps on them. The sensors on the front can be removed by undoing the star drive and carefully pulling them from the top out of the hub casting do not leaver them as anydent on the sensor surface will alter the effiency of them check that the end is not dented as chippings could possibly cause this if yu have no joy the abs module is suspect if you need any directions or advise please dont be afriad to ask kind reguards Ben Watson ps currently own 1998 v70 2,435 turbo petrol AWD estate in green and the abs system is the same.

 

A follow up.

I took the module out and sent it to Victor Rocha (http://home.earthlink.net/~vicrocha/). I highly recommend him. He responded to e-mails immediately, let me know when he received it and had a chance to look at it, provided re-installation instructions, and shipped it back within 2 days. Re-installed it and problem gone...

As for tips doing this job, take the whole airbox out to gain access to the module screws. Take the top off, disconnect the MAF. Then take the bottom of the box out, you have to remove a few hoses. There is a plastic pin in the housing going into a grommet into the fenderwall. Use long needlenose to pinch the prongs on the two mounts nearest the engine first, lift that end up, then pull the box toward the engine, pin out of the grommet.

You do need the T5 torx socket, I got one from Sears online. You also need patience. Make SURE the socket is tapped down over the heads well before trying to loosen them. You will be cussing Swedish engineers too, for using a such a stupid fastener. The head is VERY small and will get munged up easily.

When taking out, get the bottom screws out first, then top. Installing, top first, then bottom. It's a little easier that way.

So yes, we munged up one of them. Had to unbolt the shift linkage to get a dremel disc in there and grind the head off of it. It is in a recess in the module cover and you can't slot it and use a flat blade. Used a light and a mirror and 2 pairs of hands. It was like arthroscopic surgery and I was skeptical we could even do it, but we did. You can't cut the head off flush either. (insert more cussing). We did make a bit of a mess of the cover, but Victor sealed it up, and gave us another screw no charge. Great guy...

So make sure your socket is well seated on the heads first....