ECON light doesn't turn off when engine starts

[HOZY19812]

Hi There, I have an audi a3 sportback tdi 1.9 2007 model.

Econ light stays on after engine starts and does not turn off after pressing the button. I did a scan on VAG and no faults came up. I did some output tests and I got the following results with the car stationary and engine running and the econ button would not turn off after pressing it:

0.000 A A/C Regulating Valve (N280)
0.0 % A/C Regulating Valve (N280)
4.5 % High Pressure Sensor (G65)
1.0 bar Refrigerant Pressure
35.0 Feedback Value (Actual)
36.0 Feedback Value (Specified)
38.0 Minimum Position (Lower Stop/Cool)
211.0 Maximum Position (Upper Stop/Hot)
60.0°C Coolant Temperature
0 A/C Compressor Regul.Valve (N280)

The reading were obtained while temparature setting was set to 'LO', I opened the bonnet and both radiator fans are not spinning, which I believe is because the air con compressor is not activated due to econ light being on. Hope I don't need to spend £££ to have what ever is wrong fixed. Before I did the scan I was told I have a dodgy econ button, but this works while engine is not running. I was also told I maybe low on gas, which I believe isn't a costly fix.

Feeback on this will be most appreciated. Cheers

 

[NHN]

Check the pressre switch G65 iirc, on a 2.0 bkd its on the drivers side silver pipe with connector plugged in just behind the bottom corner of rad.

 

[Dannykn9]

Silly question maybe, but does your aircon need re-gassing? If empty, then econ mode would permantly stay on I assume.

 

[@udi A3]

Use KWIKFIT!!!
They offer a no fill no charge policy, If your sytem just needs gassing they can fix it for around £40-50.

If it leaks or fails to operate when filled they wont charge you! Used them twice when i was messing about with my aircon pipes!

They will be able to tell you what if anything is removed and how much they put into it or if its leaking. If they charge and it still doesnt work you have other issues, and back to fault finding!

 

[NHN]

Thats good advice tbh.

 

[HOZY19812]

Thats good advice tbh.

Thanks for the pointers guys. I tested the output of the a/c compressor on VAG and there is a clicking sound suggesting the compressor is all good. i also tried to do an output test on the cooling fans for the raditors using VAG but they did not spin when I activated the test while engine running. Maybe the radiator fans have gone and or low gas? How will I be able to tell if the G65 high pressure sensor is ok or not as no fault code was found on a scan for G65, no fault code for radiator fans or anything else related to auto HAVC.

May also need to check for leaks in system before re-gassing as suggested.

Cheers

 

[HOZY19812]

Thanks for the pointers guys. I tested the output of the a/c compressor on VAG and there is a clicking sound suggesting the compressor is all good. i also tried to do an output test on the cooling fans for the raditors using VAG but they did not spin when I activated the test while engine running. Maybe the radiator fans have gone and or low gas? How will I be able to tell if the G65 high pressure sensor is ok or not as no fault code was found on a scan for G65, no fault code for radiator fans or anything else related to auto HAVC.

May also need to check for leaks in system before re-gassing as suggested.

Cheers

Econ light was still on while I drove to Kwik fit but when they tested the econ button, it worked and the A/C was blowing cold air. Everything was working, i.e. compressor and cooling fans including econ button! Strange? They went ahead to re-gas it since the air could be even more colder with the re-gas. It did a test for leaks and none was found otherwise the re-gas would not have gone ahead. After the re-gas air con was working brilliantly. Can't really complain for a £29 re-gas at Kwik fit as thats cheap.

However next morning, I tested A/C and the econ button would not go off to activate the A/C. I then read up my manual and it implies that if the temparature is less than 5 degrees celcius, the econ button will not go off and if the econ button still does not go off when the temparature is 5 degrees or more than theres a fault with one of the A/C components. It was 2.5 degrees in the morning, so ok, I can't expect it to work. I checked later in the morning when the temparature was above 5 degrees and the econ light would not go off and no A/C working. I then took the car on a spin to warm engine and after re-starting the engine, presto A/C and fans working??

In summary, compressor not faulty, fans are working, car re-gassed and no leaks found. Can a G65 pressure switch which I have found located at the bottom corner of the radiator still be faulty with no fault found on VAG or could it be a dodgy econ button??

Cheers

 

[NHN]

Well yes it could be faulting, but with reference to the manual, I've never seen the econ button stay on in that scenario, got me thinking now lol.

Pressure switch is £50 odd at audi, some on ebay for half, maybe try it as its cheapish to test.

 

[@udi A3]

hmm. my aircons working even at 2degrees out last night. Ive just got into a habit of leaving it on auto and econ off. I guess the compressor wont kick in when its not needed.

 

[HOZY19812]

Took the car out for a spin at 3pm and aircon works fine with outside temparature at 12 degrees. Three hours later, I took it for a spin with outside temp at 7.5 degrees and air con works. According to my vehicle air compressor doesn't like to operate when tempature is below 5 degrees or when car has been in freezing cold over night. Should be useful for anyone else to refer to their manual to see what it says if compressor doesn't kick in at temparatures below 5 degrees.

I looked at the G65 sensor and does look old though VAG showed no fault code on it. Will see how it goes and replace G65 switch by buying one from Audi as they are only £10 more than GSF Car Parts, better to stick with OE parts. Thanks for your advice guys. Kwik fits £29 no re-charge no fee price is dead cheap compared to the stealers since Audi use the same type of gas machine as Kwik Fit. Thanks for the useful tips, much appreciated.