abs + brake warning + traction control = power cuts

[joss1]

Starting from cold after a layup of a few days (normal situation) engine starts fine, go to move off, call up betweeen 1000 and 1500 rpm, brake warning light comes on (on large cental drivers information panel) also traction control triangle and abs warning light, a couple of seconds later the engine falters, to settle back to idle, ( like ECU cutting power). Brake fluid is OK, I've checked the ABS fuse, also OK, I've disconnected the battery and left it off for a while, no change.

A couple of months ago something happened that may or may not be connected, car cut out at low speed, traction control light and abs light on, car would not restart, garage ran a full check, sent off the EC for install in another car, no faults at all, has run fine since up to now.

Car is 1999 avant, MTM chip, usual add ons, 60K miles.
All suggestions welcome.

[joss1]

Well Gentlemen, has any one any suggestions?

[MarkB]

Sorry I have no ideas

[UKS4APR1]

First of all put VAG-COM on it, see what codes it shows up.
My guess (and I stress the word guess!) is something to do with the ABS rings or sensors on each wheel. (VAG-COM will tell you if sensors are OK)
If one ring was not counting correctly then traction control & ABS would be kicking in to try and get the 4 counts equal again.
Ring missing? driveshaft broken?
Traction control applies brakes to slipping wheel (EDL = Electronic Diff Lock) but on later cars does it also cut power?
I only post this due to the lack of other advice!!
"all suggestions welcome"

[S4INT]

Might be your ABS control module - they are a common fault. Do you get the three warning beeps with the brake warning light on the DIS?

Doesn't explain the cut in power though?! The ABS module is quite easy to change if you can get a second hand unit and just swap the ECU over.

[mikeyquattro]

I had ABS module go. Fault comes up as soon as you start the car. My guess is the same as UKS4APR1 as when you start moving the fault occurs.

Do you have vagcom? If not look on here

http://www.frappr.com/vagcomuk/map

Someone in your area may be able to help

[oliew]

Where abouts do you live?
have you pulled each sensor out of the hub and cleaned them yet?
my abs ecu died, its defiently that as i cant connect to the ABS module on the VAG-COM so that would be a good indication on yours.
ta
Oli

[joss1]

Thanks Guys, I'm in Ireland, plenty of expertise available locally, but the S4 is a rare item here, so all suggestions appreciated. I'm getting codes read tomorrow, & will check rings at the same time.

With thanks

John