# A/C Compressor regulator Valve N280 is faulty



## Phaeton_qatar (Jun 20, 2012)

Hi Fellows,

Its been a while as my phaeton was running fine until now. My A/C usually works fine but after few mins it blows warm air. if I turn off the car and start back in 2 mins then the A/C blows cold air again. I did the scan and it showed me "00445 - Loss of Refrigerant" so I took it the dealer for a refill. Technician checked the refrigerant pressure and it was full. I verified fuse 66 is fine. It turns out that the compressor shutdown is due to faulty regulator Valve N280. Some days the cold air is fine with out any issues but some days the problem is intermittent. so I believe I don't need to change the compressor or refill the gas. VW sells the complete compressor which includes the regulator valve. Where can I buy the regulator valve N280 separately for the correct compressor model and what is the type of compressor model in our phaeton ?

Thanks
Asad


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## cbh123 (Aug 25, 2013)

A pressure check will not prove it is full.
You need to evacuate the system and weigh it. 

The symptoms are typical for low refrigerant... I would find a shop that will weigh how much r134a is in there


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## Phaeton_qatar (Jun 20, 2012)

Thanks for the reply. I took the HAVC reading using the VCDS. The refrigerant pressure is showing full bar 14.8. so your saying that this could be false positive or wrong reading ? Also "Refrigerant Loss Shutoff Count" is zero , what does this mean ?

Address 08: Auto HVAC (3D0 907 040 G)

0.0 Compressor Shut-Off Reason
108.0°C Refrigerant Temp. (G395)
14.8 bar Refrigerant Pressure (G395)
0.0 % Regulation Valve Left (N175)
0.0 % Regulation Valve Right (N176)
0.0 Refrigerant Loss Shutoff Count
1000 /min Compressor RPM
8.7 Nm Compressor Load Torque
ON Compressor Operating
0.0 Compressor Engine Disabled


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## cbh123 (Aug 25, 2013)

I know the phaeton monitors pressure in order to detect a leak, but it has to start with knowing the system is full,,
if you have both high and low side pressures being monitored with a gauge set, and watch the compressor clutch, you might see what is happening - keep in mind the P uses a variable displacement compressor... Further making understanding difficult.

I would still want to know the amount of refrigerant is absolutely correct. 

This means remove all of it (recover) until near-vacuum conditions. (You can weigh how much was taken out into recovery tank) 
Then refill with what you took out PLUS whatever was missing. This will be a perfect full charge.

The newest A/C machines can do all that in an un attended way - so no big deal for the repair shop. 

I have old manual equipment at home - it takes some time and focus to get it perfect. 

Either way, since the repair will otherwise be expensive, it makes sense to me that the car is 100% full before changing other parts.


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## invisiblewave (Sep 22, 2008)

I agree with Bruce. Your symptoms are the same as mine when I needed a recharge.


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## Phaeton_qatar (Jun 20, 2012)

Thanks Guys, I'll take it to another workshop for recover and re-fill over the weekend. it makes perfect sense to do this first since the compressor cost is like $1200 and shipping to Qatar would cost like $200 extra. i'll update the forum after few days on the re-fill solution.


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## Gabs08PHTN (Jan 6, 2011)

Hi Asad,
When you have the refill done, check that the stem valves inside the high and low pressure connectors are gas tight. One of them failed in my Phaeton and discovered it by pure chance. You can do it by spraying soapy water on them. 

Gabriel


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## Phaeton_qatar (Jun 20, 2012)

Update: so remove and refill was successful. Gas out was 460 and in was 600. No gas leakage.The compressor has not stopped and this is great in 120F (50C) temperature. Thanks for your help.


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## cbh123 (Aug 25, 2013)

Good news!


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## Bindaham (Apr 4, 2014)

I have that fault 



> 01232 - A/C Compressor Regulator Valve (N280)
> 009 - Open or Short to Ground


and also had *16* when I checked the MVBs for the compressor shutoff reason!

*16 = compressor Off (activation A/C Compressor Regulator Valve-(N280)-implausible) * (Ref: TT 87-07-93)


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