Mechanic wants to check wiring looms under the carpet

[JAYBONE]

Got the following faults which all happened at the same time

ESP Light on
Fan Runs constantly
Heater/Air Con does not work/switch on

and mechanic wants to do continuity checks on the wiring looms under the carpet, and I'm thinking the carpet will never fit the same again, any comments?

ps: He did a Fault code check and it came up with P1857, which doesn't pin point anything.

What would you consider?

[Guest 2]

What did he scan the car with?

[MarkTM]

Useful stuff to post

1) How long have you had the car?
2) Which year/engine/transmission/mileage
3) How long ago did the faults occur and did you have any work done to or changes to the car, anything as minor as changing the battery
4) Was VCDS used to scan it if not what scan tool
5) A google of the fault code brings up quite a bit, have you attempted this?

For example:
ESP Fault | Audi Forum

[JAYBONE]

It's a 2005 a6 S line, manual, with 145k miles on it.
I've had it from 2 years old and 60k miles
Engine was replaced about 2 years ago due to oil pump failure and new turbo and clutch replaced at same time
new EGR valve too!

the fault has been there about 2 weeks now and he used a Snap On fault finder.
Since the fault we replaced the MAF sensor, well I did, since a lot of people on google suggested it could be this. But nope, same fault.

not even sure it's all linked, but seems odd it all happened same time

[Guest 2]

Scan it with VCDS before doing anything else as some other tools can misread fault codes.

[gupsterg]

Got the following faults which all happened at the same time

ESP Light on
Fan Runs constantly
Heater/Air Con does not work/switch on

and mechanic wants to do continuity checks on the wiring looms under the carpet, and I'm thinking the carpet will never fit the same again, any comments?

If taken out right it will fit fine and you'll never know, only issue removing carpet I see is it has these shaping plastic pieces in it and if not handled correctly they tear out of sponge backing on carpet.

ps: He did a Fault code check and it came up with P1857, which doesn't pin point anything.

That EOBD code means

EOBD II Error Code: P1857

Fault Location:
Engine Control Module (ECM) - Load Signal Error Message

Possible Cause:
Malfunction Indicator Lamp (MIL)(K83) active.

Fault Code(s) stored in Engine Control Module (ECM).

Possible Solutions:
Check Engine Control Module (ECM) for Fault Code(s).

What would you consider?

Personally I'd not be getting carpet removed to get looms checked under it. Why I say this is I've had my interior out quite a few times and can't see why the looms under carpet would be what he'd need to access.

Looking at the EOBD code I'd be looking at ECU / Engine looms if looking for wiring fault.

As stated get a VCDS scan, in Chris's signature is a map of forum members with VCDS perhaps you can find one close to use and get one done.