"Limp Mode"? A6 Avant 2002 2.5TDi 114kw

[smg1965]

Purchased a A6 Avant 2002 2.5TDi 114kw a few months ago.
My wife reported a problem several times where the car lost all power, it just idled, and the esp and ABS (think its the abs) lights came on.
As this never happened to me I put it down to her not changing gears, from 4th to 3rd for example.

Eventually I decided to try and replicate the problem and was able to do this by being in 3rd gear, not 2nd, while going up a hill and putting the throttle all the way down for about 5 seconds at about 15mph.
The car just went into limp mode, still moving but could not accelerate no matter what gear I changed into.
This also happened on the motorway at about 60mph whilst accelerating.
To resolve the problem I have to turn the car off and on again!

The codes below are a result of this occurring.
Anyone got any ideas?
Thanks in advance.

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Control Module Part Number: 4B1 907 401 D
Component and/or Version: 2.5l/4VTEDC G000SG D04
Software Coding: 01012
Work Shop Code: WSC 02325
Additional Info: 00004059 130 106JC150_1.V77691379191
Additional Info: 00004059 130 106JC150_1.V77691379191

1 Fault Found:
00777 - Accelerator Position Sensor (G79)
27-10 - Implausible Signal - Intermittent

---------------------------------------------------------------------------
Control Module Part Number: 4B0 614 517 G
Component and/or Version: ABS/ESP front 1728
Software Coding: 06455
Work Shop Code: WSC 02325

1 Fault Found:
01314 - Engine Control Module
79-10 - Please Check Fault Codes - Intermittent

[Kyojitsu]

My guess is you need a new throttle pedal. It has a built in potentiometer that measures the position of the throttle and then sends a signal to the engine control module. As it's a moving part they tend to wear out at the point of most use which is typically low speed/stop start throttle travel. I imagine the module couldn't square the throttle position with the speed of the car and just went into limp mode as a precaution. My Allroad had it replaced and from memory it was around £90 plus labour (not a big job). Best get a specialist to check it out for you though.

[adamss24]

Where about's are you based ? The c5 platform behaves in a odd way when an overboost condition occurs. I would start by checking under the battery covers for water build-up, the water makes it's way inside the ECU box and the connectors corrode which can trigger the accelerator pedal code ! However the ABS/ESP warning light will not go on because of the accelerator pedal and it's un-related. If you're not far from London then i could scan it for you and check a few parameters which can narrow down the potential culprits ! Give me a ring on 07789912128 if you need more details...
Chris.

[smg1965]

Thanks for the replies!
Down the A22 in Sussex so not close to London.
Have a eBay VAG scanner thingy so any help on what I should be scanning for, step-by-steps would be great.
Will check water problem when it stops raining !

Thanks again,
Steve