Hi, I've been having some AC issues on my current daily driver: Fabia I, 1.4TDI PD 55kW AMF, 6Y5244, 2004.

 

Story time: last summer, I replaced a leaking condenser, had it refilled (they did some compression tests as per the regulations and said it was ok) and everything worked just fine. I ran it a few times in the winter as well, but I wasn't sure it was actually doing anything... Well, it probably wasn't, because it didn't work this year at all.

 

Current problem: The AC button lights up, but there's no drop in revs and no rise in fuel consumption, as it used to be. I have gotten an error code P0118 a few times in the past 6 months (engine coolant temperature sensor), but it usually reset itself or I did it manually with my ELM237 ebay BT adapter and it took a long time for it to reappear again.

 

What I have tried:

- found out the resistance on a working engine coolant temperature sensor at room temp is about 2.2kΩ, so I unplugged the sensor and plugged in a 2k2 resistor - no change to AC, didn't get P0118

- checked that the center of the compressor pulley is rotating

- gently tapped the solenoid valve with a hammer multiple times - no change

- read codes using multiple apps - nothing

- unplugged the solenoid valve and measured voltage on the input connector - 12.8V when the ac is off, but even when it's on (doesn't seem like there is any PWM)

 

 

Is it possible I'm not getting, say, a low pressure error, because the ELM327 is not capable of reading it? I'm not sure I got a low pressure error last year before refilling it...

Why is there solid 12V on the coil at all times? I thought there would be 0V when it's off...

Should i try to make it do something by quickly connecting and dis

...and disconnecting 12V from the valve?

Try measuring the dc resistance of the solenoid valve. Maybe it has failed open circuit?