Diagnostic worry codes?

[Stevey Y]

Hi Gents,

I have always had my own diagnostic platform which I used throughout my ownership of my Ford cabs, this saved me a shed load of money when the milage started to rack up, I got a Dunton engineer as a fare up to Luton airport, turns out this guy programs the computers that program the ECU and just about any other electrical module on the car when they are on the production line, I had a couple of recurring faults on the body control module and the ECU they were not stopping the car running but it just bugged me.

He explained that over a 100k the modules were probably rammed to capacity with redundant information and that was why they kept throwing up codes, he then suggested that if I used the as factory facility on my software and let the modules relearn their values with the existing milage this would cure the problem, it did.

Roll forward to the Audi, I bought a pre loaded laptop with a version of VCDS and the correct interface and up to about three months ago every two weeks had a plug in and cleared a lot of the one time codes I had only found one embedded code and that was for the humidity sensor under the mirror so I replaced that and the screen stopped misting up and the code never returned, three months ago the hard drive on the computer started to play around so I gave it to a friend of mine who is into anything to do with computers and runs his own repair business, he was going to fit my rig with a digital hard drive which is faster and has a larger memory.

It had been a while but I wasn't worried as the laptop was not high on my list of priorities. Two days ago he turned up at where I work highly excited and with the laptop which he informed me now loads up like a rocket, he then announced that the only information he had salvaged off of the old hard drive was my previous fault logs but not the VCDS or ETKA I had on there, but he had sourced the latest version of both and loaded them on there and now wanted a car to try it on, so being bored witless after only getting a job every couple of hours I booked a break and we plugged in, crammed in  the front with all the cables and the laptop looking like a couple of MI5 operatives on a observation mission, the newer VCDS worked really well but the end of scan had more red bits than the Texas chainsaw massacre.

None of the faults I had logged previously had appeared again with the exception of the implausible information from the clutch pedal switch which I believe is caused by me getting the wrong gear when I change down and stall it, the other faults were all new so logged them and cleared down, today I read it again and the only returning fault was for the fresh air sensor which on research seems to be a common problem, also finding its exact location seems to be shrouded in mystery, I will find it.

So in conclusion it would appear that the Audi diagnostic analysis is somewhat more sensitive than the Ford and therefore flags up the slightest communication break between modules this is worrying from the perspective that anyone who uses a dealers for servicing  may be open to abuse from the point of having to have very costly sensors replaced merely because of what amounts to an electronic sneeze and would never know if it happened again as they don't have the facilities to look at it, now here comes the clever part with my particular problem, the sensors for the climate control are all daisy chained so if as in my case one stops working the others won't work and the diagnostics cant check their functions so they operate in a state of neutral default, no lights or any warning, in my case I can smell exhaust fumes when I am behind old cars as the sensor is not picking them up and shutting the vent to stop it getting into the car. Therefore might I suggest  if you do have the car scanned get the codes deleted and try again in a couple of weeks to see if they reappear  its a damn site cheaper than keep replacing parts because the computer says so.