# ABS/ESP fault.



## barffy (Dec 4, 2015)

Hi,

I've had numerous lights on my TT in my short ownership. At first it was just the ABS and ESP which would go out if I turned the engine off and on again. With these lights on the car seemed to be unaffected and still drove fine. It always seemed to be after driving more spirited that they would come on. I then went away for two weeks and after coming home the car struggled to start but driving along with low throttle inputs the car would jerk and judder and once in traffic it cut out completely. I did a throttle body reset and touch wood it's only cut out once since. The last few days the car has seemed to have run great with no warning lights but last night the ABS/ESP lights came on again. I have just had my OBDEleven unit delivered so I plugged it in and I have the following errors on the four wheel drive system:

OBDeleven data log

Date: 2016-01-21 06:52

VIN: TRUZZZ8NZ11035846
Car: Audi TT
Year: 2001

22 All Wheel Control
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System description: HALDEX LSC ECC 0006
Software number: 02D900554B

Trouble codes:
65535 - Ctrl. module faulty Unknown
static
00526 - Brake light switch Implausible signal
Intermittent

I had plugged it in previously and cleared the brake light fault and I'm also getting a couple of errors, one relating to the passenger airbag and another relating to the aircon system pressure switch. With my limited knowledge I'm going to assume these have nothing to do with the running of the car. When I very first got the car my friend hooked it up to VCDS and we found longitudinal sensor errors and a MAF error. After clearing these and driving for the last four weeks they have not returned.

My brake lights work, I can see them coming on in my rear view so I'm not sure why I'm getting the error. Again, with limited knowledge I would assume that data from the brake pedal would definitely play a role in the 4WD system.

Two weeks ago I took it had an interim service, oil pickup replacement and Haldex service and the car has 15 stamps in the book so it has been looked after.

Any help is appreciated.


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## barffy (Dec 4, 2015)

I've done a little more digging and the '65535 - Ctrl. module faulty Unknown' when google'd actually seems to relate to the airbag, so why is it coming up under 22 All Wheel Control?!

From searching here it seems that someones car used to cut the power (as mine intermittently does) and the brake lights illuminate by themselves due to a faulty switch. I will have to keep an eye out to see if the lights come on when I experience the problem.


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## outdoor stevie (Nov 24, 2013)

I would read that as a fault in the control of the haldex, so just to make sure have you definitely got four wheel drive working, have you tested it? And then go from there.

Stevie


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## barffy (Dec 4, 2015)

It's hard for me to tell as I don't have any axle stands to jack it up and see if all wheels are turning. I thought it was working as we had a bit of snow and I had no signs of slippage even when under hard acceleration.


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## Hoggy (May 8, 2002)

barffy said:


> It's hard for me to tell as I don't have any axle stands to jack it up and see if all wheels are turning. I thought it was working as we had a bit of snow and I had no signs of slippage even when under hard acceleration.


Hi, Drive it onto wet grass, if front wheels spin & rears don't then haldex not working.
Check fuse No. 31
Hoggy.


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## barffy (Dec 4, 2015)

Thanks Hoggy, will check fuse and look for grass!


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## barffy (Dec 4, 2015)

Update (after a long time!) I scanned the car and had a fault pertaining to the MAF.The car had a poor idle and loss of power so I replaced this and didn't get the ABS/ESP fault for almost a month. I'm now getting it again but no further faults regarding the MAF. I'm also getting the occasional poor running on tick over /loss of power on acceleration again which replacing the MAF solved, for a time.

I have since verified that the four wheel drive is working using the wet grass trick. The ABS/ESP seem to come on during gentle driving after a short period of 'spirited' driving.

Scans are still showing faults with A/C which I will deal with at a later date and the same Haldex fault which has never gone away.


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## firediamonduk (Dec 24, 2013)

Normally MAF fault only causes the ESP light to come on and not the ABS, whereas a fault with ABS would normally cause both lights to come on as the systems are linked.

try data logging wheel speed sensors/ brake pedal switch and long and lat sensors and see if you can pick up whats causing the fault.

Haldex problems often caused by snapped earth strap or rusty connector to the module so worth a check if you can get under the car...

with regards to the rough running and cutting out, check all your vac pipes for leaks


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