abs trouble

[kaneelschep]

Hi all.

I have a late 95 volvo 850 t5 2litre with abs trouble.
I took the controller out and resoldered the typical contacts.
That actually worked perfectly for about a month, untill i went on a 1500km trip in +35 degrees. Gotta love the airco.
Somewhere at the end of the trip, the abs light came up again randomly.
Now it is on more then off again.
When the light is about to come on, you feel the paddle go hard and shake like abs kicking in. Then its back to normal but with the light on.
When i resoldered the controller i noticed it was one with tracs and 4x4.
Now i do have tracs if the button in the dash is correct. But no 4x4.
Could it be i have a wrong replacement controller?
I heard and read that if you change the controller to another serialnumber it will never function correctly.
Could this be my case?
Now if i give my vin and controller serial, could someone check wich one should actually be in the car?

Now my second issue is that the two wires coming from the abspump going to the controller lost all plastic insulation. I read this is very common in the volvos. I had this on the fuelpumprelais wires too.
So I tried to clean and insulate it with new tape as far as possible, but when you reach the pump it is impossible to get to the end of the wires without dissasembling the pump.
Could this be maybe be the reason for the abs light coming on?
Does someone maybe know a trick to insulate it properly so i can isolate this problem? Or any other solution?

Thanks a lot!

[Matty Moo]

As long as the module is a 9162675/9140774 then it's good to go. They put a few different labels on those modules but they're all identical. Some say 4wd, some say 2wd/4wd, etc. But they're all the exact same part. On your car they only used two modules, either TRACS or plain ABS. Either one will work in your car.

As far as the pump wires, take a small flathead screwdriver and pop off the black plastic cover on the pump motor. That will allow you to wrap them all the way to where they enter the little motor. The pump motor wiring is not going to have any bearing on the ABS kicking in like it is for you. So you either didn't solder it correctly or you have an external fault outside of the module.

When you soldered it did you make absolutely sure that every last bit of the rubber membrane was removed from that part of the board? Did you actually flow the joints properly and do all of them?

[rspi]

Could it be i have a wrong replacement controller?
I heard and read that if you change the controller to another serial number it will never function correctly.

That would be a stretch. It will work, or not work. If the unit was improper, it would NOT work for 2 days then stop working.

If I were you, even with more expensive shipping, I would send the unit to www.MidWest-ABS.com for repair or replacement. You can also get a replacement wire shipped to you for less than $15 US.

[erikv11]

... You can also get a replacement wire shipped to you for less than $15 US.

[/quote]

Cool, what is the source for this Robert? Never heard of it, and basically every 96 needs it.

[kaneelschep]

Thanks for the replies and thoughts.
After rereading my initial post, I see now I used metric km's and Celcius. Sorry for that. Good thing it was not very important for my story.

When reinsulating the pump wires I did actually take the black cover off to try and insulate them as far as possible.
So if this is far enough, then that's good.

Ok, so this must be the correct controller, or it would never have worked. That is good to know.
I was confused by the 4wd.

I flowed all contacts wich had to be flowed according to some picture I found here. But I guess I just did not do it properly or missed some.
I used a 35w soldering iron, I thought to be warm enough but not too warm.
Maybe to be sure, someone can show me on my picture wich contacts to solder?
I attached some pictures of my controller I made on my phone while working on it.

I do not recall the membrane very well..
Could you tell me more about this and how to get it off? And what to put back on after soldering.
I personally had the feeling the controller stopped working because of the heat.
Is this possible?
Average temperature on the trip was 35celcius with max of 43 celcius.
I think 40 celcius is around 100 fahrenheit?

There are companies here too wich rebuilt the controller. They charge around 125-200 euros for a replacement box with a year warranty.
I really do not want to spent that.
The local scrapyard has a few laying around too, but will probably charge me 50-100 euro for it too and there is no guarantee those will actually work.
So that is why i would really like to fix it myself. I have the time, tools, attitude and place.

Thanks!

[Matty Moo]

The clear rubber that covers the entire board has to come off in the area that needs to be resoldered. That's the area where all the small pins are.

[kaneelschep]

apart from my questions, I understand I will probably just have to reopen and resolder it.

I don't see any clear rubber on the picture and can't remember it either. Is it always there? Maybe possible the last opener left it out?
By the area with the pins, you mean the entire right area, right?

And to my hypothesis about heat affecting it.
This week it has been freezing here. And I made 2 trips of about 60miles. The Abs light never came on. But when it does, it does so when I restart the car.

[kaneelschep]

Oh and what do I put back as replacement of the clear rubber when resoldered?

Thanks!

[instarx]

The clear rubber that covers the entire board has to come off in the area that needs to be resoldered. That's the area where all the small pins are.

"Clear rubber", is that sort of like transparent aluminum"? Beam me up Scotty.

[Matty Moo]

Oh and what do I put back as replacement of the clear rubber when resoldered?

Thanks!

The entire circuit board is covered with it. It's a clear rubbery coating. You don't replace it.