Do it yourself ABS module repair. Topic is solved

[bright]

Does the 960's have a similar transmission learning mode?
Thanks,
Lee

[pkc303]

Ozark Lee,

Thanks for the post, we just completed the ABS/TRACS light on fix, following your excellent instructions. Thank you very much. The 1997 Volvo 850R is back in business.

Eric and Evan

[jj-]

I've been putting this off for a long while. I decided to go for it this weekend, but I am not sure if I was successful or not. I'd appreciate some input.

I have a 96 850 Turbo. The ABS light came on not too long after I bought the car 4.5 years ago. I didn't give it too much thought and the light eventually burned out. Probably 2 years ago the speedometer would occasionally stop working, and it eventually that led to it not working most of the time as of 6 months ago. Usually it works when you first start driving, but then cuts out a couple minutes into the trip. I was fairly certain that it was the ABS module.

I pulled out the ABS module yesterday--thanks, Lee. I used the plywood and pry method to open the unit--thanks, czechm8. It only took a couple of minutes to get it open. There were no apparent bad joints until I got the clear, rubbery coating off, which was a bit of a pain. Both power pin joints were clearly cracked. I don't think I have ever soldered a circuit board in my life, but I gave it a shot, and it is tougher than it looks. Once I was done, it was an ugly job, but I think I did it sufficiently. I put the unit back in without sealing it back up. I reassembled the airbox and went for a test drive.

The speedometer worked fine for the entire few mile drive, and it is a particularly warm day here in Nashville, so if the fix didn't work, I think it would have cut out during the drive. Because my ABS light is burned out, I don't know if it on or off. I tested the ABS by slamming on the breaks, and I locked up the wheels. Soooo, what is the possibility that I soldered the joints well and fixed the ABS module (and hence the speedometer), but that there is a different problem with the ABS system that would keep it from working properly? I would appreciate some input. I still need to decide whether to seal the unit up with silicone or have someone solder it for me on Monday in case I didn't do a good job.

[marginal]

Hi jj- .

Here's my 5¢.
Since I bought my 850 GLT 1997 my ABS does not work, the person I bought it from (a mechanic) said he's tried to disassemble the ABS sensors on the wheels without success.
My ABS fault light does not work, I have no ABS and everything else works OK (speedometer included).
While scanning the OBD II codes with a universal (not a Volvo dedicated) scanner I get no error codes.

So, that is it.

[Ozark Lee]

I still need to decide whether to seal the unit up with silicone or have someone solder it for me on Monday in case I didn't do a good job.

That is your call but the rain is heading your way - I drove through it all day in Missouri on the way home and you don't want an unsealed module in the rain.

Did you have the TRACS light before and is it now off? If so there is a 99% chance that the ABS light would also be off if it wasn't burned out.

The main power pins to the modulator pump are very hard to solder, they take a lot of heat to get the solder to flow properly. If you have not done a lot of soldering you might want to look for an electronic repair shop to have them touch the solder job up for you.

Push comes to shove go by a local radio station and ask to talk to the chief engineer. He will initially look at you like you smoke too much crack but after you explain the situation, if he is like most of the radio engineers I know, he will take about 15 minutes to fix it right up for you for free and the promotions department will give you a free bumper sticker.

...Lee

[ghalperin]

Harbor Freight sells the socket set. I picked one up today for $6.99.
6 PC. 1/4" DEEP WALL FEMALE STAR SOCKET SET
Pittsburgh
95178-0VGA

http://www.harborfreight.com/cpi/ctaf/d ... mber=95178

[schigara]

I just did the repair on my module about a week ago. Man...that sucker is tough to get the cover apart! I didn't have my heat gun handy at the time but I imagine it would have made it a bunch easier.

I tried using a hobbyist solder pen that was 35 watts and would not budge the solder on the larger pins. I went to RadioShack and got a 175/230 watt solder gun and that did the job with a quickness. I re-soldered the large pins but I just re-flowed the tiny ones.

Under magnification, I was able to see cracks in the solder of 3 pins.

Almost a week and the abs and tracs lights are still off. Also, it rained today so I was able to easily test the abs and traction control. Thumbs up all around.

[wfo48]

I just took my wife's car to check for codes reads abs module. so ,i have already cracked the case and found the pins w/ cracks (i used a jeweler's loop to see them and boy the are clear) I hope this works. The only thing is the board looks a little bit different then the posted pic ,but the ones circled were in the same spot could there be a few different kinds of boards? 99 v70 wagon w/o DSTC im going to solder tonight a take a test run..if this works she will love me...

[Digger2]

I've put in two different rebuilt modules, and the ABS light is still on, and the speedometer doesn't work.

Initially, before removing the ABS module, the ABS light and TRACS light were on, while the speedometer still worked. After removing the module and resoldering myself (I didn't see any broken solder though), I put the unit back in and the TRACS light went out and the speedometer stopped working. I sent it for a rebuild, and the rebuilt unit made no difference. They sent me a different rebuilt unit and still no difference.

Am I missing something?

Thanks for any input!

[Ozark Lee]

Make sure that it is getting plugged back in correctly, the main connector has an odd catch system and it is possible to think it is seated when it really isn't.

...Lee