A6 2.5TDi ABS warning after plug disconnection - RESOLVED

Posted: Thu Apr 25, 2013 9:07 am

Hi all,

I am so pissed off with myself Evil or Very Mad

Yesterday afternoon I took the windscreen washer bottle out to replace the pump (only to find the one I'd bought from eBay was the wrong one - but that's another story).

In order to ease access to the washer bottle, I disconnected the large multi-pin connector on th ABS unit. This plug has a metal clamp on it, which I opened, then disconnected the plug. Loads of dry detritus fell into the socket when I did so, but I carefully vacuumed all this out.

Reassembling the car, I replaced the plug. I was not surprised to get an ABS failure warning (red brake symbol continually flashing on the main display plus the amber 'ABS AUS' light on) when I restarted the car.

I called my mate at Norwich Audi who suggested that either the unit might reset itself (some models do when you drive more than 500m at more than 20kph, until all the sensors are talking to the unit) or - failing that - it would have to be reset by VAG COM.

I took the car for a drive, but the dynamic reset didn't work. I stopped at Norwich Audi this morning and waited whilst they VAG COM'ed it. Tey managed to reset the service indicator successfully, but they cannot get the ABS fault to clear.

I asked what he suggested as a next step and he suggested gettng some contact cleaner and making sure the male and female plug contacts were completely clean - he clearly wasn't optimistic about this. One frustration is that I won't know if anything I do is effective until they try to reset it for me anyway...

As it stands, the car won't pass an MOT (thankfully not due until October), so this needs to be sorted somehow.

1997 A6 2.5TDi Avant quattro - 255k miles - brake fluid replaced about 18 months ago (by Bladerunner - RIP).

Any ideas, guidance gratefully received...

Many thanks,

Mike Sad

Posted: Fri Apr 26, 2013 3:32 pm

Fixed!

I took Norwich Audi's advice and spent an hour this morning carefully cleaning all the blade contacts on the unit and the sockets on the plug. I then carefully brushed the socket out and hoovered it until it was spotless.

I reconnected the plug, started the car up and Bingo! No warning light - didn't even need to be VAG-COM'ed...

Mike Smile

Audi Nut Joined: Apr 23, 2012 Posts: 61

glad you fixed it, i have brake warning light for a year now, my plan was to install those brake pads in my old audi 100 C3 (RIP) and i cut them off cause C3 didnt have connectors, but i installed them on C4 after...

Audi Nut Joined: Apr 23, 2012 Posts: 61

2 new problems today... other 1 i will post on my old topic

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