A4 02 Climate Control Problem

**Tanuki** · 12-12-2006,01:05 PM

Just recently I had condensation building up inside and noticed that the ECON light on the climate control unit stayed on all the time. Nothing I could do would turn it off.

Anyway I took it into the local VAG specialist (not dealer) and they told me it was a failed climate control unit.

Fair enough, but the quote wasn't. £450 for a new unit NOT INCLUDING labour.

I've seen second hand units on ebay ranging from 40-100 quid. I'm now thinking of buying one and doing it myself.

How though? Is removing the unit relatively easy? Are there any online manuals? Do I have to do anything special to install the new(ish) unit.

**Tanuki** · 13-12-2006,06:05 PM

I've spotted what I *think* is the part on eBay:

PART 8E0 820 043

It mentions something about the part needing to be coded to the car.

This would confirm my suspicion. Has anyone replaced one of these themselves? How would I go about doing this myself I bought the part?

Surely someone here has some knowledge of this?

**Tanuki** · 14-12-2006,06:47 PM

As I continue to go it alone on this thread , my investigations show possibilities.

1. It's the high pressure switch, or high pressure sensor, or A/C Pressure Switch.

2. Reading other threads/forums it's either replacing high pressure sensor/switch, or resetting it. I'm interested in what needs to happen to reset it because it sounds the easiest option to try first before ordering expensive parts.

3. I could be wrong about HPS and it's the Climate Control unit that actually *is* faulty, in which case I need to replace it. And then find out some way of "coding" it in. No response yet from anyone on what I might need to do.

I'm still waiting for my diag cable that will hopefully give me a fault code. I reckon the garage was going to hit me with a new climate control unit with significant mark-up, then do something like "reset" a high pressure switch. I hope to prove this because if I do I'm shopping them to Crimewatch.

**Tanuki** · 15-12-2006,01:42 PM

Got the cable, hooked up VAG-COM:

Friday, 15 December 2006, 11:43:18

VAG-COM Version: Release 409.1-US

Control Module Part Number: 8E0 820 043 H

Component and/or Version: A4 Klimaautomat 1015

Software Coding: 00000

Work Shop Code: WSC 63351

1 Fault Found:

00819 - High Pressure Sensor (G65)

29-00 - Short to Ground

---------------------------------------------------------------------------

Well well well......

Should I take this to Audi and request they change it or take it to my local mobile air-con guy, get the part and let him change it?

How hard are the pressure switches to change?

Martin.

**craig1** · 15-12-2006,05:55 PM

glad you found your fault tanuki, where did you get your diag lead from and do you use it linked to a lap top with the software etc to read the codes, would be gratefull for your help

**Tanuki** · 15-12-2006,06:02 PM

Hey Bob,

I got the cable from this lot, then downloaded the VAG-COM software from Ross Tech to my laptop, then hooked it up to the car. It's only shareware, so I don't have full functionality, but it was enough to spot the fault. The port is under the driver's side of the dash far right for an A4 (B6)

Gendan Limited
http://www.gendan.co.uk
Tel: 01792 233491
Fax: 01792 232383

Still not sure if I'm outta jail just yet. I have to get the sensor replaced, and I don't know how nor am I sure if I need to "code" the new sensor in if I do manage it myself.

I'm tempted to buy the part, give it to my local Air Con guy to change, but I doubt he'd know how to code it in if this is necessary. I was hoping someone here would know but so far I've seen no responses.

**craig1** · 15-12-2006,06:21 PM

i would imagine you will need to get your air con guy to fit the sensor as it detects the pressure in your gas system for your air con and therfore will require re gassed when the new sensor is fitted.

i work on hgv trucks mainly and they where fore runners in can system electrics (man / volvo scania etc) like the cars are on now, i would imagine you could get away with a sensor without programming it to the car but if it was an ecu like the climate control unit it would need programmed to the car,

the sensor does what it says and keeps an eye on the pressure in your air con system hence the reason yours wont work as it cant read the pressure and has shut down the air con system and put you on to econ mode i would think,

just wish i could find out how my a4 front bumper detatches from the wing so i can get my timing belt done asap sitting at 61k just now dont want to leave it to long, hard to get feed back on this forum i have noticed

**Tanuki** · 15-12-2006,06:58 PM

Yeah I know what you mean. I miss the Subaru forums.
If I spot any workshop manual stuff for removing the front bumper I'll let you know.

**adamss24** · 15-12-2006,08:01 PM

You can replace the sensor yourself. Its a simple screw-in job. If its still don't work, check the coolant temp sensor as if faulty it will trick the ECU into thinking that its too cold and it will switch the A/C off. Look for chuffed/dirty conectors/wires.