I own a 2000 S80 T6 - no sympathy please - I should have read some of these threads before buying this beast - but it's mine now and I'm trying to enjoy it until I can sell it....

I'll spare you all of the details, but after two blown turbos, new brakes, struts, and tie rod ends - I am now struggling with an "abs module" problem.

My story starts out like many of yours - intermittent Brake Failure - Stop Safely ASAP warnings, along with check engine and brake light flashes....once they started staying on all the time, I started researching what can be done about it and what the culprit might be. In all my research, most of the thoughts pointed towards a bad ABS module and that there are several reputable folks who can repair them. Turns out, after being rejected by 3 rebuilders - I have the DSTC module (2% of these ???) and it can't be rebuilt??? As a result, I purchased a refurbished module and installed it. Same problem persists - dash board lit up like Christmas.

I have heard some say it could be wheel speed sensors - not exactly sure how to check them - can I hook up an ohm meter to them to check for continuity?

Anyone need the refurbished ABS module I purchased?

Anyone have any direction for me at this point? Ideas?

Next stop - the driver's door lock actuator is now bad....

Thanks to anyone who can provide some self help direction on this thing.

Regards!

Craig

 

You can connect an ohm meter to the sensor and spin the wheel and see if the meter sees the wheel moving.

 

Great idea - any help on where the electrical connectors are for the rear wheel sensors? I can't quite follow them up from the rear wheels.... I found the front two easily enough...

 

On the rears, the sensor is screwed into the back at the 12o'clock position. I had my wheel hubs replaced with an inferior brand that didn't allow my sensors to function, thereby my dash lights were lit up. Another brand cured the signals and all lights were fixed.
Check that the screws are tight. I read somewhere that the screw was loose causing the dash lights. Too bad you don't have a scanner in which it would tell you which wheel is giving you the error.

 

537 - I'm actually looking for where the wire from the sensor connects to the harness. Like on the front sensors, the wires go from the sensor, up into the engine compartment where they can be disconnected. Trying to locate this for the rear sensors.

I did have new tires and brakes installed and this problem may have started shortly after this. I've been dealing with issues for over 2 years and the darn car spends most of it's time in the garage...can't recall the order of events.

I think I had a bunch of front end work done -tie rod ends, sway bar linkage, struts, new tires on all 4, rear brakes, etc. This was all done in August/Sept 2008. My first inquiry regarding a bad ABS module was in November 2008. Any thing sound suspect here?

 

I forget where the rear ones plug in at.
Check the ABS rings on the front axles. What codes are coming up?

 

Sorry, it's been two years since I had the codes checked....this thing has been ******* me. Is there a good procedure to use for cleaning the wheel speed sensors? I haven't been able to find one yet. Thanks!

 

Best is to remove them and clean them using brake cleaner.
The rebuilt module you bought was the codes cleared before they sent it to you?

 

I have no idea if the used module I bought had the codes cleared before it was sent to me....what does it take to clear the codes? Do they have to be manually cleared?

I reinstalled my original ABS module today to put things "back to normal" as I saw no difference with the "new" one that was installed.

Tell me more about clearing the codes if you have the time.

Thanks!

 

I'm not to sure that the sensors are your problem like in my case. But the harness connection for the rear sensors is actually under the rear seat cushion. Remove the cushion and you'll see them.

 

You need to find someone that has a scanner that can read the ABS system. Then they can clear the codes.

 

Hey Tech,
I have the DTSC on my car too, and I had it rebuilt by BBA Reman. I have had bad wheel speed sensor codes ever since. Is it true that they can't rebuild the DTSC module? BBA never said anything about that.

 

im wondering if you have the same problem i had...abs lights were on when i start the car and whilst driving they sometimes went off randomly. brake failure stop asap.....anyway, i removed the abs module and it looked fine, i did re-solder the points mentioned on one of the threads i seen and put it back together and it seemed to work fine and still is working.
one thing i noticed when i removed the module was the dirt around the big conector to the abs module....so i used some WD40 and cleaned it up, not sure if that was the original fault.

just passing some info, hope it helps

 

I have never heard of the DSTC ones not being able to be rebuilt. Maybe the sensor is not working correctly.

 

Niether Vic Rocha nor ModuleMasters said they could rebuild it - on second thought, I don't think I sent it to BBA-Reman. However, I bought a refurbushed one from somewhere (I wish I could remember from where) and it didn't solve the problem....Sound like I better pull the codes....

 

@tinkering: Thanks for the thoughts, I'll pull the module out and make sure its good and clean.

I actually bought one new sensor and tried it out on both sides hoping that one of the two was the problem. Still have the codes. I'll try the cleaning thing, but I will probably get another sensor too.

Thanks for the help.

 

Ill keep my fingers crossed for you

 

@ckiggins
I had to replace the drivers side lock actuator recently. Bought it thru partsgeeks I think. Anyway, I mentioned the outcome a little on this thread. Maybe it will help.
https://volvoforums.com/forum/volvo-s80-18/vibration-during-acceleration-wheel-speed-sensors-41176/

 

This is a big time shot in the dark, but is it maybe the CEM? Although I think that would cause all sorts of engine problems too.

 

I have not had my problem resolved - instead I have just lived with it for a couple of years....It's a third car and we don't drive it much, but I'm tired of trying to troubleshoot it on my own. Next step is the dealer, but I'm not ready to go through that. I am hopeful that it is just a wheel speed sensor, but what a crummy system if it reacts that way when a sensor like that goes out - can't they just say that? Instead, cruise doesn't work, the odometer doesn't work, and the dash is all lit up with warnings.

Let me know if you have any luck on your end - would like to get this resolved eventually!

Craig