I have a 2004 Volvo S80 t6. Can anybody tel me how to get to the ABS module and if it is the same as the ones being discussed here? I have the same problems and was told by my mechanic a year ago that it was teh ABS module. They checked all the wheel sensors and other connections and determined it was the ABS.
Thanks
VenturaS80

 

IF you can hook a scanner up to it and read all the codes this would have been solved a long time ago.

If you have any ABS wheel speed sensor faults, and the connector is intact and dry, and the sensor itself is secure and not physicality damaged it is ALWAYS the ABS module.

At this point a NEW module may be your better bet. Also for every year there are 2-3 different ones. You must make sure the numbers match. Second, when installing the new module, afterward BEFORE starting the car, did you clear all codes in all the computers?? If you didn't it is going to hard program whatever code that is in the ABS computer into the module and essentially ruining it (module memory can be cleared, very difficult)

I have put on probably 12-15 modules this month and all having the same complaints as yours, all of them went smoothly and it was the module.

Unless a wire got pinched somewhere, or the ABS computer is bugging out, those are the only 2 things that can also cause those issues.

You need to remember, all the computers are linked together and talk and read off each other. You have to clear all codes in all computers/modules.

 

Thanks for the candid response - I probably COULD have had this fixed a long time ago, but being a 3rd car, it was never a priority. Obviously I should take this to a volvo repair facility as I purchased a ABS Module on line to replace the "faulty" one, and after installation, was having the same error messages. Probably didn't clear fault codes, etc. Thanks again for posting - glad you're here!

Craig

 

no communication occurs when there is not enough voltage to from the battery for the computers.

In your case you should put that battery on a slow charge for a few hours while doing a hard battery reset.

FFR: disconnecting something with the power on (key on/pos1/off battery connected) will not caluse any issues. If the engine is running and something is disconnected, you will have a code for it.

 

do a hard battery reset.

 

CEM and all computers will be reset when you do this :

hard battery restart.

key off

remove positive battery cable first

then the negitive

take vise grips and clamp the 2 ends together

suspend -- DO NOT LET THEM TOUCH THE BATTERY

let it 30+ minutes Longer you let it sit like that the deeper the reset goes into the computers. Its not uncommon that I do this over night.

its a good idea to keep a trickle charger on the battery when doing the reset 10A or less is fine. If the battery does not have a full charge the reset is pointless.

reconnect the negitive cable first.

TURN KEY TO POSITION 2 "on" do not try to start.

reconnect positive battery cable. you will hear everything in the car acctulate. This is normal.

start car immediately after reset. DO NOT TURN THE KEY BACK OFF. turn to start position from position 2.

 

there is another way to try resetting the ABS module if the hard reset didn't work. However it involves turning the car off and on while driving down the highway and I DO NOT RECOMMEND YOU DO THAT.

with the modules its a manufacturing defect in the curcit board inside when they go they are usually gone. Very rarely do these procedures work, but they are worth the try.

(I know grammer is bad. its early and I didn't make my codffee strong enough.)