# Aircon help!



## John-H (Jul 13, 2005)

My aircon packed in ( http://www.********.co.uk/ttforumbbs/vi ... hp?t=97377 ) and having done some output tests with Vag-Com I get the following:

*00604 - Potentiometer Positioning Motor for Air Flow Flap (G113)
30-00 - Open or Short to B+*

Now, I've not taken it apart to check yet but having read some info I'm unsure whether this might be a red herring.

Can anyone tell me if this can cause the aircon to fail to blow cold air and if G113 is fitted to a 1999 TT 225 Coupe?

Thanks


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## Wak (May 6, 2002)

From what I can see the G113 is a positioning sensor for the V71 flap.

V71 flap regulates fresh air or recycled air so I would guess this shouldn't effect the A/C operation.

:?


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## John-H (Jul 13, 2005)

So it can't block it off completely. Bu**er! That's more serious like it's sprung a leak or something - but wouldn't the output tests have shown up something else if there was no pressure or the compressor wasn't working? - all the other tests passed!

I got no trace of any flourescent dye anywhere so was thinking it wasn't a leak.


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## John-H (Jul 13, 2005)

I'm a bit confused over this. Bentley says about G113 sensor / V71 motor - "This flap motor moves the fresh air/recirculated air flap in addition to the air flow flap." So what's the airflow flap? Could this block flow completely?


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## Wak (May 6, 2002)

John-H said:


> I'm a bit confused over this. Bentley says about G113 sensor / V71 motor - "This flap motor moves the fresh air/recirculated air flap in addition to the air flow flap." So what's the airflow flap? Could this block flow completely?


I'm guessing from the description that it would only change fresh air to re-circulated air both should be cooled if the a/C is working.

can you definitely feel the a/c clutch engaging?

Do the fans run as expected?


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## Wak (May 6, 2002)

do you get any code on the CC display?
http://www.quattro.lv/old/climate.html


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## John-H (Jul 13, 2005)

Wak said:


> ...I'm guessing from the description that it would only change fresh air to re-circulated air both should be cooled if the a/C is working.


I was thinking one flap toggled between recirculating and fresh air and the other flap controlled any air flow through the unit. i.e. it could block off airflow. i.e. I'm clutching at straws :wink:



Wak said:


> ...can you definitely feel the a/c clutch engaging?


Not sure how and when. I presume I should be able to feel the compressor with my hand during the Vag-Com output test? I've not tried this. I've not noticed the engine falter like with my Escort but it's much smoother and proportional it seems on the TT.



Wak said:


> ...Do the fans run as expected?


The aircon fan at the front turns on and cycles up and down in speed during the output test.
Oh that reminds me... I presume these tests are to be manually stepped through and out of? I find if I leave it too long running a test it times out and reports an error.



Wak said:


> do you get any code on the CC display?
> http://www.quattro.lv/old/climate.html


Now here's confusion... Firstly, I thought Vag-Com should be better for reading any trouble so had ignored the climate control readout possibilities. Secondly, only some of those codes seem to make sense on mine e.g. 49C for coolant temp for example.

When I select "52C" I get "0" with the engine running and "16" with it stopped. For "53C" I get "0" with the engine running and "10" with it stopped. Obviously this channel is completely different - the display is a dot matrix and not a "8" seven segment display with decimal point for alpha numeric interpretation as in the explanation.

I'll have another look at 1C to see if it brings up anything - I'd not checked this before. When I previously did a check with Vag-Com the Aircon control module reported no faults. I've come fully kitted today with tools and laptop for an attempt at repair at lunchtime :roll:


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## John-H (Jul 13, 2005)

Right, been out testing again...

The Climate Control channel 1C reads back fault code 15.3 = "Airflow Flap Motor Potentiometer, sporadic open" according to the list.

So much the same fault.

I ran the output tests again and couldn't notice anything happening with the compressor but the test sequence isn't obvious.

1/ It first says click start/next for the cooling fan and gives a warning about the fan starting up. The fan is NOT running at this point.

2/ I click start/Next and the fan starts up but Vag-Com displays *Compressor magnetic clutch* whilst the fan test is running. :?

3/ I click Start/Next again and nothing seems to happen with the compressor but some other test is displayed at this point.

To cut a long story short the compressor doesn't seem to be working.

How can I tell if this is due to a lack of refrigerant or electrical? Could the compressor not be working for another reason?

During testing V71 flap motor (linked to G113 potentiometer fault) I can hear clicking - or was that clicking from the previous test title :roll: I do wish people would think about their interfaces more when designing software :roll:


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## Wak (May 6, 2002)

I'd need to spend time on wiring on this, but I think the compressor is driven by the fan controller.

If you have bentley then look into the wiring but I guess the next step is to test if the compressor wiring is getting a feed to trigger it! :?


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## John-H (Jul 13, 2005)

Wak said:


> I'd need to spend time on wiring on this, but I think the compressor is driven by the fan controller.
> 
> If you have bentley then look into the wiring but I guess the next step is to test if the compressor wiring is getting a feed to trigger it! :?


Yes, I'll concentrate on that area next - thanks!


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## John-H (Jul 13, 2005)

Update: I've not had much time lately to work on this but managed to get some time last night.

I tested the compressor clutch coil and it reads about 3 ohms or so (4 Amps) but there is no 12V across the connector driving it when the aircon is turned on.

In addition my coolant run on pump had packed in and I noticed there was no 12V driving that either.

This points to control module J293 - but the aircon fan is working which is also driven from here :? .

A forum search seems to indicate confusion as to its location - Bentley says by the radiator on the passenger (left) side.

I notice the wiring diagram says (188) earth connection in loom for the run on pump but I can't see where the return for the clutch is at the moment (only 2002 diagram on line - was sure my year showed an earth). Just wondering if it's a common earth problem - should have checked the earth last night :roll: .

Aha! - Just discovered that fuse 16 was blown! I'm sure the fuses were the first thing I checked. Perhaps I looked at the wrong one :roll: . Fuse 16 is for the aircon clutch - and it seems the run on pump. This does not seem to be documented as far as I can see. Very confusing seeing as the fans worked but the clutch and pump were taken out. Anyway - replaced the fuse and now it's all working - cool 8)


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## ryanmtt (Sep 13, 2010)

Sorry to drag up an old post but I am getting the same symptoms

I have checked

Fuses
Mag clutch 
Rad fans
It's been topped up and rechecked and it's holding gas

The only code I get is 00604 so I have ordered a new part from Audi and it's wrong

I have no idea what to do next

Cheers


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## PlasticMac (Apr 25, 2017)

What part , that is incorrect, did you buy? Was it Air Flow Flap Motor?
Mac.


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## ryanmtt (Sep 13, 2010)

It was yes the part number was 1J0907511 and I have discovered I need 1J0907511A

The part I bought was the correct one on Etka


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## PlasticMac (Apr 25, 2017)

Other than the scan, can you summarise the "physical" symptoms you have please?
Mac.


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## ryanmtt (Sep 13, 2010)

Hi thanks for the reply I have no cold ac and a intermittent coolant run on pump


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## PlasticMac (Apr 25, 2017)

ryanmtt said:


> Hi thanks for the reply I have no cold ac and a intermittent coolant run on pump


Do you have full air flow out of the vents, despite it not being cold? If so, vary the air flow path (auto/>< etc) and note if they work. This is to check the movement of the various flaps. 
Mac.


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## ryanmtt (Sep 13, 2010)

Thankyou for the reply's all flaps seem to be moving no funny noises or anything and if I switch between different positions it's the same air flow just warm


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## David C (Apr 15, 2013)

ryanmtt said:


> Thankyou for the reply's all flaps seem to be moving no funny noises or anything and if I switch between different positions it's the same air flow just warm


Does that warm ness change with coolant temperature?


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## PlasticMac (Apr 25, 2017)

David C said:


> ryanmtt said:
> 
> 
> > Thankyou for the reply's all flaps seem to be moving no funny noises or anything and if I switch between different positions it's the same air flow just warm
> ...


... and, when blower is on max, does it feel like full flow, or as if flow is restricted?
Mac.


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## ryanmtt (Sep 13, 2010)

It's hard to say really but if I'm honest it does feel warmer when the car is up to temp

It doesn't really feel restricted I don't think but as it's warm air and not cold air i don't think it's as powerful air flow as it was

Cheers


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## David C (Apr 15, 2013)

ryanmtt said:


> It's hard to say really but if I'm honest it does feel warmer when the car is up to temp
> 
> It doesn't really feel restricted I don't think but as it's warm air and not cold air i don't think it's as powerful air flow as it was


and when the engine is up to temperature, if you turn the temperature up does the heating get properly HOT?
or does it just stay "warmish"?


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## ryanmtt (Sep 13, 2010)

Pretty much the same between lo and hi I will take the car for a drive and report back... did not even think about putting temp to hi


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## ryanmtt (Sep 13, 2010)

It's really hot on hi not just warm but like someone has lit a fire behind the dash


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## David C (Apr 15, 2013)

ryanmtt said:


> It's really hot on hi not just warm but like someone has lit a fire behind the dash


ok, so the airflow flap is moving for temperature adjustment.


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## PlasticMac (Apr 25, 2017)

David C said:


> ryanmtt said:
> 
> 
> > It's really hot on hi not just warm but like someone has lit a fire behind the dash
> ...


I think the flow flap (if there is one, I think it's just blower speed that controls flow) and the temp flap are separate. If so, the temperature flap is good (controls how much warm air is mixed with ambient air coming through the evaporator). Assuming it's closing when you set lo temp on AC, air flow (volume) is good, but air is not getting cold, sounds like the evaporator is not getting refrigerant flow through it.
Mac.


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## David C (Apr 15, 2013)

PlasticMac said:


> David C said:
> 
> 
> > ryanmtt said:
> ...


Sorry, I meant the flap that controls the temperature.

We're talking about the same thing anyway!


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## ryanmtt (Sep 13, 2010)

These are both really good info

Cheers both


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## John-H (Jul 13, 2005)

ryanmtt said:


> Sorry to drag up an old post but I am getting the same symptoms
> 
> I have checked
> 
> ...


When you say you checked the magnetic clutch was that just an electrical solenoid coil resistance/continuity test - or did you look to see if the compressor drive shaft was being engaged by the clutch? You should see the locking nut and centre part spin and there should be a noticeable click and momentary hesitation of the engine as the clutch engages and drives the compressor.


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## PlasticMac (Apr 25, 2017)

AC System Self Study. Helps to understand what the bits do (or don't).
Mac.


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## BrianB (Apr 15, 2016)

Sorry to jump in on an existing thread, my air conditioning stopped working on the way back from Nottingham on Wednesday. It was fine for an hour but stopped just before joining the M6.
Followed John H's suggestions and with econ selected the magnetic clutch does not engage no sign of it turning on the end of the compressor. 
The after run coolant pump works as normal so have ruled out fuse 16 on end of dash.
I'm thinking the fan control module maybe at fault.
Question, if I disconnect the plug at the magnetic clutch and connect a multi meter will I see 12v when selecting econ on and off to be able to eliminate the FCM?
And is it possible to connect 12v directly to the magnetic clutch and see it moves in and out slightly as it engages?
Apologies once again, any thoughts much appreciated.

Regards
Brian.


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## John-H (Jul 13, 2005)

Hi Brian,

Don't forget ECON is for "economy" i.e. air conditioning = OFF so the magnetic clutch should NOT be engaged when the ECON indicator light is ON.

Both fans should be running at least at low speed if air con is ON.

Yes you can test the magnetic clutch by applying 12V and see the compressor shaft turn (don't leave it running like this as there's no pressure control)


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## ryanmtt (Sep 13, 2010)

John-H said:


> ryanmtt said:
> 
> 
> > Sorry to drag up an old post but I am getting the same symptoms
> ...


It was visually checked and tested with a multimeter

The locking nut and pin both spin and there's definitely a clunk when the mag clutch engages and the revs drop briefly


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## John-H (Jul 13, 2005)

If your compressor is compressing continuously and you have some speed fan flow through the front radiator/condenser then if you also have airflow through your evaporator you should get cold air if your cabin fan is on and your pollen filter isn't blocked. So if you don't, either the flap isn't diverting air through the evaporator or there's a restriction in the refrigerant which would tend to cause excess pressure and the compressor would be cut out by the high pressure switch - so if it's turning you'd expect flow is happening. If refrigerant flow is happening without enough air exchange you tend to get ice forming in the evaporator and a stinking hot condenser. There's a metal block on the bulkhead with tubes connected that should be covered by an insulation cover. This should be very cold if things are working and a missing cover can reduce performance with a hot engine bay. I don't think that's your problem though if it's not working at all.


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## PlasticMac (Apr 25, 2017)

I suggest getting an aircon specialist to look at it. They can measure the flow and return pressures. If there is little or no flow of refrigerant, the flow and return pressures will be much the same. The problem may be the integral control valve in the compressor. It electrically controlled, but if the coil is OK, but it's mechanically duff, maybe it won't trigger an error code.
Hopefully, a basic check will not cost much ...
Mac.


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## ryanmtt (Sep 13, 2010)

Thankyou all for the help

Funny you mention the block at the back on the bulkhead there's not cover on there and I'm sure there was when I was changing the pipes over to silicone last year


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## John-H (Jul 13, 2005)

Yes mine fell off once and I found said mystery object on the undertray. Took me a while to work out where it cane from :roll:


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## BrianB (Apr 15, 2016)

John-H said:


> Hi Brian,
> 
> Don't forget ECON is for "economy" i.e. air conditioning = OFF so the magnetic clutch should NOT be engaged when the ECON indicator light is ON.
> 
> ...


Thanks for the reply John,

I meant to say when deselecting econ (air conditioning on) that the magnetic clutch doesn't engage. I have also run a full vcds scan with no faults found with the HVAC system.
Away for a few days so will investigate further when back.
Thanks again, Brian.


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## TT Grant (Apr 24, 2018)

QUOTE 
I meant to say when deselecting econ (air conditioning on) that the magnetic clutch doesn't engage. I have also run a full vcds scan with no faults found with the HVAC system.
Away for a few days so will investigate further when back.
Thanks again, Brian.[/quote]

**********************************************************

The Solenoid Magnet may have failed if the clutch is failing to engage.
Simple to check if you can access the two connection wires.

The unit will have either shorted & popped a fuse in the vehicle, or failed open-circuit.
This solenoid coil does get hot, as the internal coil resistance is usually between 6 @ 12 Ohms.
If your test meter does not bleep when checking continuity, then it is definitely a burned out solenoid coil.

This coil is possibly replaceable without removing the AC-Pump dependent on access.


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## BrianB (Apr 15, 2016)

TT Grant said:


> QUOTE
> I meant to say when deselecting econ (air conditioning on) that the magnetic clutch doesn't engage. I have also run a full vcds scan with no faults found with the HVAC system.
> Away for a few days so will investigate further when back.
> Thanks again, Brian.


**********************************************************

The Solenoid Magnet may have failed if the clutch is failing to engage.
Simple to check if you can access the two connection wires.

The unit will have either shorted & popped a fuse in the vehicle, or failed open-circuit.
This solenoid coil does get hot, as the internal coil resistance is usually between 6 @ 12 Ohms.
If your test meter does not bleep when checking continuity, then it is definitely a burned out solenoid coil.

This coil is possibly replaceable without removing the AC-Pump dependent on access.[/quote]

Thanks for the reply, hopefully will have a chance over the next few days to access the plug and do some troubleshooting.
I don't think it could have shorted because my coolant after run pump works fine and they appear to be on the same fuse (No16)


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## jules13 (Jan 3, 2021)

Hi there, sharing my problems with AC (APX engine 1999 here), maybe will help someone.

Like the original op, I had 00604 error in VCDS and AC was not working.
Changed blown fuse no. 16, changed fan relay though the fans were ok but wanted to be sure, repressurized AC system several times, still no current was coming to AC clutch.

Began to wonder how V71 potentiometer G113 could cause this, and I'm sure now it has nothing to do with it.

Problem was that fuse no. 16 is for the auxiliary water pump also, as mentioned on the thread here.
And turns out that the fuse was blown again by this auxiliary water pump, have to replace and check wires.
Disconnecting the aux water pump and replacing the fuse, AC engaged imediately, blowing nice cold air.

So, conclusion is check the fuse even if you changed it, and if blown again disconnect the aux water pump.

PS: many thanks to guys here on the forum (like JohnH, Huggy, Wak and others) for imparting their knowledge, helped me alot. Still lots of work to do on my car and would be alot harder without this info.


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