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Do it yourself ABS module repair. Topic is solved

Help, Advice and DIY Tutorials on Volvo's P80 platform cars -- Volvo's 1990s "bread and butter" cars -- powered by the ubiquitous and durable Volvo inline 5-cylinder engine.

1992 - 1997 850, including 850 R, 850 T-5R, 850 T-5, 850 GLT
1997 - 2000 S70, S70 AWD
1997 - 2000 V70, V70 AWD
1997 - 2000 V70-XC
1997 - 2004 C70

This topic is in the MVS Volvo Repair Database » Do It Yourself ABS Module Repair
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THeOldMan
Posts: 8
Joined: 28 November 2010
Year and Model: V70 1998
Location: Los Gatos, CA

Re: Do it yourself ABS module repair.

Post by THeOldMan »

Hi Lee,
How did you ever get the ABS module box to open? Do I have to somehow remove the bolt sleeves? If so, how do I manage that? I took off one of the fasteners but that did not help. I get stuck at every one of the four bolt holes.
Thanks,
Paul

Ozark Lee
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Post by Ozark Lee »

Welcome to MVS Paul,

I just cut the retainers around the bolt holes in half with a Dremel tool cut off wheel - that is the easy part. The hardest part of this job is getting the module open. The retainers aren't really critical after you silicone the module back together.

Once the module is open it is pure cake to fix it if you know how to solder and have a big enough soldering iron.

...Lee
'94 850 N/A 5 speed
'96 Platinum Edition Turbo
Previous:
1999 V70XC - Nautic Blue - Totaled while parked.
1999 V70XC - RIP - Wrecked Parts Car.
1998 S70 T5
1996 850 N/A
1989 740 GLT
1986 740 GLT
1972 142 Grand Luxe

THeOldMan
Posts: 8
Joined: 28 November 2010
Year and Model: V70 1998
Location: Los Gatos, CA

Post by THeOldMan »

As soon as I hit send, I figured I'd go at it again, popped the retainers and successfully opened the box. I've reheated all the joints. I'm not too confident that it will work because of one tiny glitch while opening the box. The surface mount resistor farthest from the power pins was loose and I suspect that it is because I hit it while attempting to open the box. I soldered it back on as best as I can tell but my eyesight is not so good... I recommend Dremel-type saw or hacksaw, not srewdriver and hammer to open the box. I'll let you all know. BTW I used a 5/32 socket which worked well. In any case, I figure that I'm no worse off than before this attempt since my ABS quit six years ago, cruise two years ago, and speedo last week.

Update:
Took it for a quick spin before sealing it all up. Speedo works! ABS light is off! I didn't go far enough to test the cruise control, I'll do that tomorrow if I get home from work early enough. Looking good!!

Update:
No luck with the cruise control, perhaps there is something else wrong with it but I have speedo and no ABS light so I'm a happy camper. I won't know if ABS really works unless I can find a parking lot with ice which is thankfully quite rare here. I used washers on the bolts when I put them back on just to be extra cautious.

Jtnb
Posts: 13
Joined: 3 December 2010
Year and Model: 2014 frontwd XC70
Location: New York City, Connecticut

Post by Jtnb »

Hello All,

Thanks for the informative thread. Here's my particular version of the issue and I'll keep it brief. Any help would be greatly appreciated.
  • 2001 V70, approx 180k.
    ABS, Trac lights lit. ABS Service Required on display.

    Removed computer (thanks Ozark Lee!), resoldered, resealed, and reinstalled. Started car, no lights. YAY! Feeling VERY good about myself...

    Drove about 10-15 miles. No warning lights. Parked car for several hours and when wifey took her out later on the lights were all aglow again. From joy to sadness. I rechecked all the connections, including the camming-type connection for the main control cable. Really not much else to do.
The only other related symptom is a slight brake fluid leak, probably from the valve unit above, but it's very, very slight. Reservoir is full and braking is solid.

BTW I have driven the car with the module out and I get the warning: "Brake Failure. Stop Safely ASAP." Braking does not appear affected, so I'm thinking this is a red herring. Doesn't inspire confidence though, given that the e-brake is also non-functional.

Any ideas, anyone? And thank you for all your great information, all of you.

Jonathan in Branford, CT.

marginal
Posts: 320
Joined: 23 September 2009
Year and Model: V70 D5 2003
Location: Ladarevo
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Post by marginal »

Hi Jonathan ...
Why don't you try to disconnect the battery for at least half an hour and see.
Maybe there's some memory left in the system.

Matty Moo
Posts: 1810
Joined: 12 October 2008
Year and Model: 850, 1996
Location: Ann Arbor, MI
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Post by Matty Moo »

go back and reflow every pin that you originally did.

there are 5 other sets of pins on that board. there are 4 pins in a line on each set. check each one. On some of the modules I've come across, they didn't do that great of a job at the factory and you'll have to add a touch of solder to some of those pins. you have to be careful though, they're real close together and they can't touch.

Don't use RTV or regular silicone to seal it back up. Use something non-acetic such as butyl rubber or GE silicone II. I fix quite a few that have been fixed before, and the acetic-based silicone really eats things up inside.

I'd take a pic, but don't have one cracked open right now.
Image
http://www.midwest-abs.com
Simplycleanpowerwash.com

1996 850 Platinum Wagon. ARD Green Tune, OBX.-Gone
1998 s70 ARD tune, EST exhaust, SE/R interior.
1999 s70 Plain Jane.
2000 s70 GLT
2014 Ram
2012 Jeep Wrangler Unlimited

Matty Moo
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Post by Matty Moo »

Re-seat the large multi-pin harness a few times also. It never seats correctly.
Image
http://www.midwest-abs.com
Simplycleanpowerwash.com

1996 850 Platinum Wagon. ARD Green Tune, OBX.-Gone
1998 s70 ARD tune, EST exhaust, SE/R interior.
1999 s70 Plain Jane.
2000 s70 GLT
2014 Ram
2012 Jeep Wrangler Unlimited

Jtnb
Posts: 13
Joined: 3 December 2010
Year and Model: 2014 frontwd XC70
Location: New York City, Connecticut

Post by Jtnb »

Thank you, Matty Moo. I will do as you suggest before crying uncle and mailing the whole mess off to Vinnie.

1. The corrosiveness thing was a surprise. You are absolutely right about that. I found this: http://yarchive.net/electr/silicone_sea ... eness.html and read the whole thing. Makes it VERY clear that most silicones we have access to are not at all suitable for this application.

2. Does anyone have any thoughts about the "Brake Failure. Stop Safely ASAP" warning I get when the computer is out? Brakes appear to be working fine, but I'm hesitant to drive with that scary language staring at me. Can anyone share their experience?

Jonathan

Mtnhorse
Posts: 3
Joined: 23 May 2010
Year and Model: V70 T5 1998
Location: Santa Cruz, CA

Post by Mtnhorse »

Boy was I glad to find this article. My son's 1998 v70 had the ABS light come on and the shop wanted too much to replace it. With the Great information here, I decided to try it myself.

The one tip I wanted to share was how I opened the unit. I have a dremel tool but I didn't want to mess with it indoors on my dining table. I took my swiss army knife and put the blade in the crack and tapped it with a small hammer. I was able to feel when it broke through the wall inside so I didn't go too deep and just worked my around it. When I got all the way I took a screwdriver near the posts and gave it a little twist to break the wall behind it. I had it opened in less than 10 minutes.

I saw the cold solder joints on the power pins only but decided to redo all of them. I been doing electronics work all my life so is wasn't a big deal.

I put in back in today and the ABS light went off shortly after I drove it down the street.

This site has saved me a bundle. I've be making a donation as soon as I post this.

Thanks!!!
Gary

1998 v70 t5

jmailloux
Posts: 74
Joined: 26 January 2010
Year and Model: V70R 1998 Silver
Location: San Diego

Post by jmailloux »

I did this a month or two ago. I recall having to remove the air box and the hose from the airbox to the turbo. I used a small 1/4" drive ratchet I have with the E-5 Torx socket. Was a pain on the bottom (or driver's side) bolts, but I had enough access. My ratchet is probably only 3-4" long, so that might be the key. Make sure you get the Torx socket on straight, as you don't want to strip it.
Good luck.
Jim.
_____________________________
1998 V70R Silver 180k

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