UK-POLOS.NET - THE VW Polo Forum

Hi Chaps

Hope you can help me basically the air-con has stopped working. The climate control panel now flashes when you 1st start the car up i know this means there is a fault with the system.

I have plugged it into vagcom and its saying pressure switch short to ground. Anyone have any idea where this switch is? Or does this mean there is no gas left? The compressor still engages when you turn it off ECON inside.

Flashing is generally a sign of a fault

Whats the exact fault code with the P number? It could well be out of gas.

I had a similar problem it was the G65 pressure sensor that was furbarred but my compressor was not running is yours deffo running have a look at the pully when its switched on and make sure the inner bit is spinning (I hope that does not make me look like I am teaching my grandmother to suck eggs)

If you take off the grill round the fog light on the drivers side and remove the fog light, look up into the void and you can see the air con pipe work rising up. The sensor is on this just below the level of the head light. If you need to get it off you can remove it from there with a stubby 17mm (I think) spanner.

Before you do all that though check to make sure you have the correct pressure in the system

Hope that helps

Thanks mate will have a look at it now I know where I'm looking. Be nice for it to work as it should you were right the compressor is not starting up when you turn it on.

So something is not happy!

Its defo the sensor. Same fault with it plugged in or out. Also when i took it off it shot off so there is defo some gas left in there!

When I got my cambelt done by a vw specialist they commented that the aircon wasn't working (it is) and left a note on the invoice about it needing a switch and service for £135

So I took it back and they said it was a small/slow leak and to keep an eye on it

Is this the switch/sensor mentioned above? My car is a 9n3 gti with climate control

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My CC has just started flashing on start up! What a weekend to pack up

I haven't vagcom'd it yet, what code should I expect?

The fault will show in engine on vagcom. My fault was high pressure sensor open to short (G65). I've got a new one on the way hopefully it will fix it!!

The fault will show in engine on vagcom. My fault was high pressure sensor open to short (G65). I've got a new one on the way hopefully it will fix it!!

slarner wrote:The fault will show in engine on vagcom. My fault was high pressure sensor open to short (G65). I've got a new one on the way hopefully it will fix it!!

I'll plug it in tonight then. How much was the sensor? And how much for a re-gas nowadays?

6n2stan wrote:

slarner wrote:The fault will show in engine on vagcom. My fault was high pressure sensor open to short (G65). I've got a new one on the way hopefully it will fix it!!

I'll plug it in tonight then. How much was the sensor? And how much for a re-gas nowadays?

the sensor was £26 on eBay P/N - 1K0959126B I think a gas round here is around £70

Scanned the car tonight and I got this from the Auto HVAC: 00792 - A/C Pressure switch (F129)

Ross-tech just points me to the said switch failure? Is there only the one or have I got a different snag to Slarner?

Its the same thing, Mine did the same. when I scanned HVAC for faults it came up with that fault code but when I scanned the engine for faults it came up with the other one (about the G65 sender) I looked into it and found that the G65 does both jobs it detects high and low pressure in the system, if you unplug it it will show an open circuit if you bridge the connectors on the plug it will set the fans running to high speed because it thinks the system is over pressurized. I think it must have some sort of potentiometer inside it that varies the voltage back to the fan control unit so the air con can work between a higher and lower limit of pressure, if it exceeds either it then throws a fault code up. Interestingly the pipes can have a bit of pressure in them but still not work and still not throw a fault code, I think it has to be over 25psi for the fan and compressor to kick in.

I posted a link to a web site that had shed loads of info on these cars in my thread, I will see if I can fin it

Its here and the link is at the end of the thread, I am not sure now which one they call ours on the web site (MK 3 or Mk 5) and its a bit of a pain to navigate with lots of empty pages, just keep clicking next page and it will get to it.

http://www.uk-polos.net/view ... =7&t=59401 this is the thread its on

6n2stan wrote:Scanned the car tonight and I got this from the Auto HVAC: 00792 - A/C Pressure switch (F129)

Ross-tech just points me to the said switch failure? Is there only the one or have I got a different snag to Slarner?

Also go into engine on vagcom then go fault codes it will say in there. But that is the same fault my hvac was showing.

It is the sensor I changed the sensor today and boom the air con is now working again the climate control has stopped flashing and you can hear the compressor running!