Do it yourself ABS module repair. Topic is solved

SilverBullet · Post by **SilverBullet** » 23 Mar 2009, 13:42

I'm attempting the module repair and after looking at it, it looks like it was opened already.. there is what appears to be clear silicone around it.. Could this be the owner before me bought a rebuilt one? Oh yeah, and the fuse on mine is the #4 fuse in the main compartment under the hood.. not the fuse compartment in the cowl area... that one is #4 as well.. do i pull those?

SilverBullet · Post by **SilverBullet** » 23 Mar 2009, 23:10

Well i attempted it today and it seems all went well.. some one else was in it before me and only did two of the big ones... upon looking at the little ones that were circled in the pics, i noticed i had 10 pins that needed solder. i soldered them put it back together.Oh yeah and before i did the fix my codes were p1618 and p1633 and p0000. I put the code reader on and automatically the 1618 and 1633 were gone without me clearing them. so i cleared the p0000 code and the check engine light is off and so far staying off and the code reader say no codes "ready". Took it for a test drive and all the gauges work fine.

Thank you for the awesome write up!

my850isbeat · Post by **my850isbeat** » 19 Apr 2009, 10:34

Great how to article. I did the removal, resolder yesterday then siliconed it back together, gave it a few hours to set and reinstalled it this morning. Works great. I had four codes for rear speed sensors 313,314,323,324, this eliminated all of them. The only main broken solder I saw was at the 2 big ones at the pump, but I hit em all just to be safe. Junkyard wanted $250 as soon as I said Volvo. I figured with all the posts of how speed sensors rarely fail (let alone 2) I went straight for the module, and it worked, many thanks. I did have to remove the whole ABS unit because I stripped the lower back bolt, and had no choice to get it out. But is working

PierreC · Post by **PierreC** » 19 Apr 2009, 11:53

Help please!

I did the repair to the ABS controller as per this post - no change and ABS light remained on. Then bit the bullet and ordered a new ABS controller from IPD - still no change and ABS light still shining in all its glory ...

Where to from here ...?

C@lvin · Post by **C@lvin** » 19 Apr 2009, 12:13

Do you have a CEL? What codes are stored?

Which of your vehicles is having this problem?

driver60 · Post by **driver60** » 19 Apr 2009, 21:40

I have a 1998 S70 T5 which has the TRACS light lit unevenly. The brightness of the light flutters. The ABS light has never been lit. When the car is not moving the TRACS light will go out if I press hard on the brake pedal. The light will stay out for as long as I hold the pedal down but return to fluttering when I ease pressure on the pedal. Does this point to anything besides the control module?

Post by **MadeInJapan** » 20 Apr 2009, 15:18

Sounds like the wiring to the ABS light bulb is shorting somehow to one close by- probably the brake light wiring.

PierreC · Post by **PierreC** » 22 Apr 2009, 10:41

C@lvin

I guess that was an open-ended post ... thanks for bringing me down to earth!!

It is my 850 that is giving the problem ... and no, I do not have any ODB codes. To cut a long story short, Volvo only returned to South Africa in late 1994, and there were few 850's sold, and fewer still running here! None of the dealers who I frequent to service my XC and the S60 still have the equipment to read and interpret the ODB codes of the 850 - or so they claim. I know for a fact that not a single one of the 3 or 4 dealers within reasonable distance of where I live, have any skills or experience on the 850 ... so rather than having them mess up the car, I have reverted to doing my own maintenance and occasional repairs. Fortunately it is a "spare" car so it does not matter too much if it runs "on crutches" -- e.g. with ABS not working -- or if it does not run at all for a week or so.

Maybe I have to bite the bullet and buy an ODB reader from eBay ...?

Regards, Pierre

C@lvin · Post by **C@lvin** » 22 Apr 2009, 16:01

Pierre,

I have had some odd ABS problems that I was eventually able to resolve.

I am not an expert, but here are some suggestions.......

Have you checked to make sure your CEL bulb has not burned out? Normally (but not necessarily always), you'd get some kind of code which would activate the CEL.

Check your alternator, battery and all your positive and negative battery cable connections. In my 99 Saab, I had ABS lights for months and only occasionally a CEL Code. The problem turned out to be a badly corroded positive battery cable which was apparently causing electrical malfunctions usually without tripping a code.

In my 99 V70, I chased an ABS problem for months including having the controller rebuilt and trying out a loaner controller without resolving the problem. The problem turned out to be a missing axle nut which caused the wheel sensor to be out of adjustment (distance from pulse wheel). However, I did have OBD trouble codes for missing wheel speed signals.

Have you tried to engage the ABS by slamming on the brakes? Perhaps your ABS is OK, but you have a shorted wire that makes the warning light stay on.

Without a DTC, you don't have much to go on. The ABS system really isn't that complicated, though. You have wheel sensors connected by wires to your controller which monitors relative wheel speeds among the wheels and engages the pump when it detects the need for ABS.

Do you have VADIS? If you'd like, I will try to look up the pin-outs for the ABS cable harness and you can check some of your voltages and impedence of you wheel sensors to look for clues.

Post by **misha** » 23 Apr 2009, 09:16

I'm preparing for "resoldering work" on my abs module this week.What kind of silicone i need to use on circuit board?I think Lee mentioned something about "rtv silicone"?I'm i right?What means "rtv"?Radio-television?
Thanks.

Do it yourself ABS module repair. Topic is solved

Re: Do it yourself ABS module repair.