Climate Control Temp.

[PeteRR]

Hi Folks,
I've got the Automatic Air Conditioning system in the S4 that may, or may not be working correctly. I've noticed that unless its set at 'LO' I get a hell of a lot of heat coming through, even with it set at '18 Deg C.'.
It seems like it may just be delivering the highest temp on anything other than the 'LO' setting.

Is there a temp sensor or something that manages the heater output to maintain a selected temp?. If so, whereabouts is it?.
Would Vagcom or any other diagnostics help determine if somethings amiss?

[~Delta]

Sensor is behind the tiny grille on the dash, or in the roof console.

[PeteRR]

Cheers Delta, I shall have a look if some dirt or dust is obscuring the sensor.

ISTR from somewhere that these aircon systems had diagnostics, anyone know if that's the case?

[Corey]

CC diagnostics for the brave

Press and hold the recirc button and press and hold the up arrow.
Release the buttons and the display will show "01c" you are now in diagnostics mode, press the recirc button again and see what codes are being stored.

If you are having heat issues then it will be related to one of the 3 flaps servo's not woking, it is possible to get them working again though, I fear a trip over to Lincoln may be in order for you

[PeteRR]

Cheers Corey, I'll give that a whirl and see what comes up (hopefully not much!).
I may indeed be making a trip over soon.

[PeteRR]

CC diagnostics for the brave

Press and hold the recirc button and press and hold the up arrow.
Release the buttons and the display will show "01c" you are now in diagnostics mode, press the recirc button again and see what codes are being stored....

8.5
13.7

I hope it's nothing too serious!

[Corey]

8.5 is the servo motor under the wiper cover in the bulkhead and 13.7 is either the red or blue servo motor behind the centre console.
Basically they need the slip rings cleaning up and clearing of carbon from them, all a bit of a PITA to get to.
Very common for them to fail.

The codes are listed as

8.5 Temperature Regualtor Flap Motor position sensor (G92) static open
13.7 Footwell/defroster flap, sporadic block

[PeteRR]

******!, Cheers for the info though.
How much would something like that cost for your good self to fix Corey?

[Corey]

As long as we can get the motor's working again it would only be a couple of hours labour to do.
The ones behind the console involve all the centre console being removed and all the bracketry behind it being removed, if you have a radio code remember to bring it as the radio has to be removed, it is a good time to replace all those blown bulbs while in there also.
The one under the wiper cover under the bulkhead, isn't a problem to do just fiddly.

[porkkis]

Corey knows his stuff apparently. So just a bit OT. Cleaning the sensors isn't a bad idea. Also checking the operation of the dash sensor vacuum motor is a good thing to do.

And the reason why it still gives you cold at "LO" eventhough the heat flap motor is dead is that there is a vacuum operated valve on the heater line.

I think some of the B chassis RHD cars have a similar valve, but only RHD. Strange. Can anyone explain why and what controls it as the RHD cars never had the automatic climate control?

[PeteRR]

Nice one Chaps, one more job for the new year then possibly.
I only really noticed something was wrong with it when I was slowly being cooked with it set at 18 deg.C!
I may even source a new motor or two, especially for the 'dead' temp control one.....


P.S Do you mean LHD Porkkis?

[porkkis]

No, I mean RHD. I have a LHD and know everything about it already

[Corey]

I may even source a new motor or two, especially for the 'dead' temp control one.....

The 3 motors are

4A0 820 511 Blue
4A0 820 511A Red
4A0 820 511B Black

All priced at £83.94 + VAT each but they can usually be rescued by cleaning the slip rings on the end but it does involve stripping the motor's.

But what do I know???

[PeteRR]

The 3 motors are

4A0 820 511 Blue
4A0 820 511A Red
4A0 820 511B Black

All priced at £83.94 + VAT each but they can usually be rescued by cleaning the slip rings on the end but it does involve stripping the motor's.

But what do I know???

Quite a lot it seems!
Worth trying to rescue them first then. It'll be nice to have it all working spot-on again.

Funny really, my Dads Range Rover has just gone in for much the same thing, called Blend-motors in this case. Mucho spondoolicks!

[Corey]

Worth trying to rescue them first then.

Very much so

It'll be nice to have it all working spot-on again.

Getting the motors working as they should would cure the problem.