Air conditioning fault codes

Little Dog

Little Dog

A2OC Donor
European-Union
My A2 has been to the local garage to have its air con gassed this morning. Approximately 60% of refrigerant had been lost but there was still lubricant in there and the system passed pressure and vac tests. The system was charged with the correct amount of refrigerant and lubricant and then started.

I immediately noticed the fan didn't start and the mechanic noticed the compressor clutch didn't activate. He connected the car to a Bosch diagnostics device and it reported:

The fan was starting but it didn't

0333 high pressure sensor short to earth

0259 central control flap pos. sen. open circuit / possible short

The last fault I suspect relates to the direction of air in the cab but should not stop the air being cooled? The fan not working is a diagnostic exercise to determine if the cause is the fan, controller or control wiring. Have I got this correct and can anybody offer advice?

Fault 0333 is a concern, I think it relates to a sensor on the condenser behind the bumper? Would anybody have any experience of this fault and how to correct it?

Refrigerant has been removed from the system so that it is safe to work on.
 
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I recently replaced this sensor on Terry's car as it had shorted out. Be wary, when diagnosing the fault, I replaced the fuse and ended with an engine compartment full of smoke. To say my heart dropped through my bottom end is an understatement!

Audi have released a superseded sensor and it's bumper off to replace. A good idea is to replace the restrictor valve and all mini seals at the same time. You will also be shocked at the state of your condenser - it takes quite a beating at the lower end.

blue skies
tony
 
Purchased my silver 1.4 Tdi in January 2010 (59,000 miles) from Burton Bradstock cars Dorset. It would appear they have contact with Audi dealers and are prone to buying up these little cars. Fortunately it came with 2 years additional warranty(at a price!)
Come the summer there was no cooling from air con. Had it re gassed -seemed OK. At this time was self employed using a van so the car was rarely used-about 2000 miles per year. Next summer 900 miles on no air con. Took it back paid to have regassed an 2 schraeder? valves. Shortly after no air con. Under warranty major labour to access heat exchanger. An £800 plus bill.
Last year whilst driving the air con quickly lost its cooling effect and am now wondering where to go to get a lasting result. I bought this car as I was always fond of this model. I am in my 60's and I would like to see this as my last car, so cheap to keep parked at home not being used much! I have use of a small camper for those retired picnic/days out, so mileage now is about 5.000 miles per annum. I live in Luton, Bedfordshire and have used MK Audi for ABS switch failure. Was very pleased with their service. They may not be cheap but sometimes you are happy to pay to get the thing sorted! Anyone know an air con specialist for Audi A2 or do I go main dealer?
 
You're welcome to give us at A2 Cars in Milton Keynes a try.
We'll have a look at your A/C and throw in some free-bees.
PM me for details.

blue skies
tony
 
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Well Pollenmonkey1 I've now had two AC failures and both after the car has had an easy life for a while. Could be coincidental but my feeling is AC is happier when it is being used.

I have a fan failure and so have one on order, I can't imagine how difficult it is going to be to fit but I'll make an assessment when I have the replacement part.

Tony yes you are right the pressure sensor is a bumper off job; even to check out the existing sensor so I ordered one. I'm sure the seals and restrictor valves are good advice but I couldn't stretch to that after having had to order the motor.

Anybody got any experience of fault 0259?
 
hotstuff said:
I recently replaced this sensor on Terry's car as it had shorted out. Be wary, when diagnosing the fault, I replaced the fuse and ended with an engine compartment full of smoke. To say my heart dropped through my bottom end is an understatement!

Audi have released a superseded sensor and it's bumper off to replace. A good idea is to replace the restrictor valve and all mini seals at the same time. You will also be shocked at the state of your condenser - it takes quite a beating at the lower end.

blue skies
tony
Click to expand...

Hi Tony

I have the valve but it does not have a seal. Do you remember if there should be a seal or does it seal metal to metal?

Thanks

Phil
 
Another question or two.

To remove the bumper do I have to remove both front wheel arch liners and the engine bay under tray?

I have a fan but it is not the fan that is at fault. The fan relay is presenting 12V to the fan but it does not start. If I bypass the relay the fan starts without any problems. I don't know if I have a problem with the relay or switching signals to the relay. Could anybody advise how to diagnose?

Thank you.
 
I can answer some of my own questions:

If the bumper is eased forward on the O/S only the HP valve can be replaced. Only need to release the front part of the wheel arch liner.

The high pressure sensor does have a small O ring. I unfortunately didn't have a new one so the old one was reused.

It would help if someone could point me in the right direction regarding this question:

"I have a fan but it is not the fan that is at fault. The fan relay is presenting 12V to the fan but it does not start. If I bypass the relay the fan starts without any problems. I don't know if I have a problem with the relay or switching signals to the relay. Could anybody advise how to diagnose?"

Thanks
 
A2 fixed. The AC high pressure switch also appears to effect the operation of the fan relay. I replace the AC high pressure switch and the fan relay started operating normally.:)
 
Phil,

Good to hear you got it sorted out.
I have the same problem with mine, do you have a part number for the G65 sensor as I've heard there are two different versions?

Steve
 
Catnip64 said:
Phil,

Good to hear you got it sorted out.
I have the same problem with mine, do you have a part number for the G65 sensor as I've heard there are two different versions?

Steve
Click to expand...

Hi Steve

The part number will be on my receipt but that is in my wife's car and she is at work now. I thought there were two designs for the AC HP switch, the original and the new revised design?

Before you start this job I would recommend you get a selection of Audi fixings; the push button rivets, screws (two sizes) and speed nuts. Many of my speed nuts had disintegrated and the screws were well on their way.

Phil
 
Phil,

Thanks, I had a closer look yesterday and can identify the sensor, it can be seen quite easily after removing the bonnet at the top RHS of the condenser. I ordered a replacement, the part number is 3R0 959 126.
In addition, I think the replacement will be a doddle to fit as the old one can simply be removed by tightening a jubilee clip around the largest part and by using a small socket, I can rotate the sensor sufficiently to loosen it. I can then spin it off and use the same procedure to fit the new one.

All done, I reckon I can do this in 5 minutes without and need to remove the bumper :D

The new one should arrive tomorrow so will see how I get on, I'll take some pictures and post them to show the process.

Steve
 
My only top tip as to the secret to longevity on your AC is to keep it on all the time and dont use the 'Eco' button. Believe me there is very little difference in fuel consumption as I can still get 74mpg on a run. In the 12yrs I've had these cars I've never turned off the AC and run it on Auto all the time.

My last foray turning the AC on/off was on an A4 which cost me a new compressor just outside the 3yr warranty!
 
Catnip64 said:
Phil,

Thanks, I had a closer look yesterday and can identify the sensor, it can be seen quite easily after removing the bonnet at the top RHS of the condenser. I ordered a replacement, the part number is 3R0 959 126.
In addition, I think the replacement will be a doddle to fit as the old one can simply be removed by tightening a jubilee clip around the largest part and by using a small socket, I can rotate the sensor sufficiently to loosen it. I can then spin it off and use the same procedure to fit the new one.

All done, I reckon I can do this in 5 minutes without and need to remove the bumper :D

The new one should arrive tomorrow so will see how I get on, I'll take some pictures and post them to show the process.

Steve
Click to expand...

Just now found the receipt, yes that is the part number. I think the revised part has a much larger hex drive on it so I suspect a deep socket will drive it on/off.

The jubilee clip idea is really good and should work on the old switch. I stripped my car down much further than I needed to replace all of the rusted screws and speed nuts. The replacements were soaked in the brown Audi cavity preserving wax. Should never have to replace them again.
 
Foghorn said:
My only top tip as to the secret to longevity on your AC is to keep it on all the time and dont use the 'Eco' button. Believe me there is very little difference in fuel consumption as I can still get 74mpg on a run. In the 12yrs I've had these cars I've never turned off the AC and run it on Auto all the time.

My last foray turning the AC on/off was on an A4 which cost me a new compressor just outside the 3yr warranty!
Click to expand...

I agree the problem was that my AC HP switch failed in the winter so I didn't know the AC compressor clutch was not engaging, until the weather warmed up recently. All fixed and working well now though.
 
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