Do it yourself ABS module repair. Topic is solved

[andyleonard]

Yeah. Ran it down the canyon for a few miles...maybe 5 minutes. Over 20 the whole time. No pulsing, light still on. One guy posted he had to drive for a while??? No codes visible.

I don't have it all sealed up and snugged down with 4 bolts. Could that be it?

[Ozark Lee]

The sealed up part shouldn't matter (for testing purposes) but it does need to be reasonably snug up against the mounts for the solenoids to work correctly. Though not common the solder joints behind the solenoids themselves had been known to fail as well. The pins on the main power connector to the hydraulic pump motor take a lot of heat to get solder to flow - it can look OK and still be a cold joint.

...Lee

[StarryTripper]

I'm continuing on a question posted in a new thread as this seem more appropriate place now

https://www.matthewsvolvosite.com/forums ... =1&t=22867

I have the Module out and open, do I need to remove the board from the rest of the enclosure?

I've soldered many thing, but I'm confused on what to do here and how I know when it's broken or fixed

[Ozark Lee]

Once you have the cover off you are golden. Fire up the soldering iron. There is no need to remove the PC board itself.

Most of the time soldering the bad joints works - sometimes the module actually has a bad component and at that point it falls into the "just busted" category.

...Lee

[StarryTripper]

Well I got it repaired!

I don't know if it was actually broken as the bulbs were dead before I pulled it out, but their was paper work in the glove box from previous owner having it at dealer noting that the ABS Module needed replaced and owner declined repair. Also, it drove horrible last winter (it's first year with us) and ABS had never kicked in.

I put it back in just to test, haven't sealed it back up yet and only put the bolts finger tight.

The ABS & TRACS were still on, so I figured I'd drive it and see, after only a hundred feet or so & only 10mph they went out and did not come back, also the TRACS switch is working.

Once I get it all together I'll go slam on brakes and parking lot and see what happens.

Thanks for great info!

[andyleonard]

O.K. everything's resoldered, ABS pump works with direct 12 V, power plug's been checked repeatedly, multiconnector in properly, all fuses good...and no pump check at 20 mph and ABS light still on. Am I in the lucky small percentage that has a bum computer?

Any more tricks before the wrecking yard?

[seanm3113]

Well, I finally had the time to take it out again. My first repair lasted exactly a week. Since during that repair I put a new coat of silcone over the board, it was impossible to remove all that silcone this time. I did what I could. Tested it out and the ABS light went away. Drove around a little more and did not come back. Sealed it up, let it dry. Drove around again, no problems.

Wife went to work this morning, and ABS light came back. Oh, dear.

I did notice it said 4WD on my ABS unit, and I do not have 4WD. Is it possible that the previous owner threw in the wrong ABS unit? Does anyone know how to cross ref the numbers?

[misha]

If you have traction control(tracs).... it's correct one.It's stamped/written on mine too.

I guess you have some sort of other problem with your abs ecu beside bad soldered connections.

Did you checked all of your fuses for abs.I think there are 3 or 4 fuses for it.Check them all.

Good luck!

[seanm3113]

I'll check the fuses again, but the two I pulled out seemed fine. I did not think there were more than two. I suppose it could be a faulty wheel sensor..?

[Ozark Lee]

I suppose it could be a faulty wheel sensor..?

It very well could be, either that or the reluctance rings on the axles / hubs are packed up with crud and the pulses aren't registering. Unfortunately on your car the only way to tell for sure is to get the system scanned with a Volvo specific code reader. The dealers all seem to treat you like chump when you come in for a scan.

...Lee