I'm just getting back to the Volvo after an extended trip out
of town.....
Has anyone gotten the cover off of the ABS controller module
without cutting or breaking it? I've removed the clips (similar
to "toothed washers") that were pressed over the metal tubes
that the module mounting screws run through. I've also run a
knife around the cover seam to remove any sealer/adhesive.
I've tried to pry the cover off with a screwdriver but all it's
doing is chewing up the plastic, the cover doesn't budge.
I really don't want to cut this thing open with a saw, and I
don't want to pound on a module that has a history of problems
with a hammer...

John

 

Hey John, I was wondering about you! I hope you're well. I'm back in Japan and have seriously been depressed. I really hope to get back to North America before too long.

I found a Japanese web site where this person has actually opened the ABS module for repair. I'll attach pics & translation. Note, however, that this was done on V70, but I assume it's pretty much similar to 850, so I'll attach a circuit diagram (which you may also have in your Haynes manual):

Pic-1:
Remove the star washers x 4. The cover is glued onto the housing with silicone-resin and this does not come off simply by prying.

Pic-2 & 3:
Next, remove the resin with a sharp knife/screw driver slowly, around the entire housing. There are no lock tabs, but takes quite a bit of force to remove (cut through) the resin. Do not insert the tool deeply into the housing, as this will damage SMDs. I used what is called "Mac opener (the tool in the pic)"

Pic-4:
The circuit board is coated with transparent silicon film. The opposite side is mounted onto the housing, and requires unsoldering at the connector (x30 spots) and the solenoid (x14 spots) with unsoldering tool & a suction-type solder remover. This is a major work.

Pic-5:
The circuit patterns seem little to narrow for this type of module. As you cannot see the circuit pattern from the top side, expect the job to be time-consuming. The wheel sensor patterns should be the last to inspect, but re-solder the connector socket for the wheel sensors( x8 spots). For soldering, I've used a 20W solder iron. This time I have removed the clear silicone film for re-soldering. For the silicone film removal, I used a plastic scraper and a pair of tweezers.

Pic-6:
The connector pins for wheel sensors are as follows (they are for V70 and may be different on 850. See attached circuit diagram on the next post):
LF: Pin-11 & pin-4
RF: Pin-18 & pin-3
LR: Pin-2 & pin-10
RR: Pin-1 & pin-17
*The pin configuration does seem different on 850, according to the schematic.

Pic-7& 8 & 9
It is best to re-solder all connector pins (circled in red) as they are noted for cracking. The first repair failed after 6 months, so this time I used a 60W iron and used plenty of solder.

Pic-10:
I've also re-soldered other areas to ensure correct operation.

Pic-11:
After re-soldering, clean the varnish produced by the solder, apply clear electrical circuit silicone compound and smooth it out. Leave it for 24 hours before putting the cover back on. Finally, put the cover on. Apply silicone sealant onto the mating surfaces, put the cover back on and wipe off excess compound.

Re-installation Notice:
It is tricky to reconnect the large connector, as it has locking cover. If this covered is opened too wide, inserting the connector will become difficult. The cover moves as you press on the inside of the hinge, so use a small screwdriver to press on the hinge while reconnecting.


I also did some research on 850 throughout Japanese web sites, and the ATE's ABS modules were guaranteed to fail, due to poor manufacturing and the fact that it's suffering heat & vibration damage; one of the worst enemies to electronic devices as you know a lot better than I do. But some of them noted that the damage is usually around soldering, so you may be able to re-solder some components or test them with your DMM.

P.S: Tech has not been available for a while. I'll list you with the last thread Tech has posted.

https://volvoforums.com/m_56118/tm.htm

Welcome back!


Kanji, a.k.a JPN

 

The latter half of the pics & schematic (more to come):


JPN

 

The last attachment.

For those who are about to say "you'd better get a rebuilt module or have it repaired & upgraded":

Please note, that most ABS/ECU repair or upgrading services deal only with '96 or newer vehicles and they do not deal with older vehicles. I myself have contacted "Vicrocha" and have received a curt reply saying that he does not deal with '95 or older vehicles. However, if you know a place where they'd provide such services, please let us know.

John:
I'll have to delete the schematic, as it is courtesy of Volvo. I'll delete it within the next 3 days. In case if you could not save it in your PC, let me know and I'll post it again.


JPN

 

Hey Kanji,
Good to hear from you again. I'm sorry to hear you are depressed,
I hope you are doing better now. I did not know you were going
back to Japan, I hope you make it back to the states soon. I always
enjoy hearing from you.
The procedure for ABS controller repair that you posted is excellent (as are all your posts). This is the most complete
explanation I've seen and was exactly what I needed. Thanks
a million for translating this and posting it, I'm sure many other
people will be grateful also.
It's strange to not have tech posting on the forum, I hope
everything is ok for him and his family.
I've just gotten back to the Volvo. It's developed an oil leak
at the junction of the engine/transmission. I'm just hoping it's
not the "leak of death" rear main seal.
I'll start another thread on a PCV question I have in case
someone else has a similar question.
Thanks again Kanji and take care.

John

 

Wow great instructions, Thanks
I opened up my ABS controller on my 1999 C-70 and using an antistatic wrist band, microscope, and solder iron, I re-soldered the broken solder joints in the unit. Worked great.

Rgds
Henri

 

If anyone has the pictures that were once part of this thread I would really appreciate getting a copy of them. They can be sent here: bob_forte@comcast.net

 

We will have to see if JPN can repost them.

 

The new forum format has done a great job of deleting the attachments.


JPN

 

Sorry man!!

Just FYI I have been doing some I did the wifes and am doing some for the new job.

 

Good to know that it was of some use.

The original credit goes to this Japanese gentleman but I cannot remember his URL.


JPN

 

does anyone have a picture of where the ABS module is located on a 97 960 ?

Thanks

 

The 960 ABS modules are different.

 

I tried opening the ABS unit but the plastic is getting chewed up with no success. Does anyone has any suggestion for good tool? I see the mac opener (pictured above in comment #2) would be great but I could not find it or similar tool anywhere.

 

Does it take any special tools to get the ABS module out of the car?

 

RSPN
It takes a torx socket E5 and a 1/4 rachet. I am getting my set from IPD today. Choose them as for $30 it has 11 sizes, E4-E20 compared to Walmart's 10 size options (E4-E18 or E5-E20).
Also here is a link on how to do the removal.
Volvo_ABS_removal

 

will the car still be able to stop with the module removed? just asking because i cant afford not to have a car.

 

The brakes will function as normal, but abs will not function, and most likely will set an abs code...

 

thanks a bunch now i just need to remove it and have it refurbished

 

Would appreciate pin schematic for the 1995. I'm going to collect the failed module from the mechanic right now, so I can try to fix it over the weekend.