ABS warning and Brake Red Warning - power supply fault??

**martink** · 02-06-2009,07:21 PM

im after some help please guys...
car is a '99 A6 avant 2.5 v6 tdi AFB auto/tip quattro

owned since sept last year and its been pretty good to own/live with.

sent it in for discs and pads all round 2 weeks back and since then its been intermittantly giving the 3 loud beeps and red brake warnig on DIS screen and ABS yellow light.

now this comes on at various points when driving, and nothing particularly causes it as far as i can see.
sometimes during driving it will go off and the dash returns to normal.

i assumed that maybe the pad warning sensor cables may be to blame as nothing ever occured before the brakes were changed.

garage went over it today, a local indepndant garage i trust.
they say they eventually found a fault code relating to a intermittant power supply problem on the dash panel.
they say it appears to have been cleared in the past as the history shows...i assume they use Bosch kts diagnostic gear...

they say that it shoudl only affect the abs NOT working when it s lit up with warnings.

they say a repair on teh instrument panel would be required to fix it.

so does anyone have any ideas?
garge diagnosis seem correct?
anyone know any repairers that are known to have fixed this problem on the panel?

cheers guys

**a8 tech** · 02-06-2009,08:06 PM

do you have any fault codes in abs,what fault codes in dash this sound more like the very common abs control unit failing

**Crasher** · 02-06-2009,08:14 PM

Will the ABS talk to the diagnostic computer?

**a8 tech** · 02-06-2009,08:16 PM

good point Crasher

**Crasher** · 02-06-2009,08:19 PM

You thinking dead ABS ECU too?

**a8 tech** · 02-06-2009,08:21 PM

yes,over looked on the scan test so they may have missed it

**Crasher** · 02-06-2009,08:36 PM

At least it is cheap to fix with so many companies offering the service. The Audi parts departments annoy me a bit when they force people to have a new combined pump and ECU saying that is the only way when the ECU is separately available and shown on ETKA, tis a bit naughty.

**a8 tech** · 02-06-2009,08:38 PM

agree,we fit the control unit

**martink** · 02-06-2009,10:05 PM

nope i didnt get any codes or anything, i guess they can try find the codes but its bosch diagnostic not vagcom...
whats teh score with the abs unit and what needs changed/how much etc

**Crasher** · 02-06-2009,11:50 PM

The point is CAN they communicate with the ABS unit or is it refusing to communicate, this is a very important point. It isn’t just no fault codes, we need to know if the fault code reader will see the ABS ECU or if it says no comms.