My 2008 Petrol skoda fabia does not cool after 35-40 minutes. The Ac blows out air but it's not cool.

 

Last year I had changed the compressor and condenser and the problem started since then.

 

Earlier my mechanic had connected a relay switch as a temporary solution to this problem connecting the compressor directly to the power without the ecm claiming the ecm was at fault. Ac worked but i was not happy with the connection as it worked only on setting 2 and fan didn't work. So i made him reverse it.

 

I have now changed ECM and Fuel pump but the AC problem continues to happen. To start the AC again I'll have to switch off the vehicle for a while and then start only for it to work for a few more minutes. Please help.

First 30 minutes the cooling is really cold. Scanning shows no error. Is the compressor faulty. Is it the evap sensor? 

It sounds like the condenser is getting heatsoaked, you need the fan to come on at full speed to cool it during hot weather.

This happens during very cold climate too

Both cooling fans should come on at full speed 5-10 seconds after the AC is switched on, if the refrigerant level is low then the high side will not go above the 10 bar (example, depends on temperature) threshold to trigger the fans.

16 hours ago, Zaid said:

Is it the evap sensor?

Set yourself up with VCDS lite (free download from ross-tech.com) and a suitable kkl cable (cheap) then you can probably see from the compressor shutoff code in HVAC module measuring blocks what is inhibiting the cooling.

 

Here are the Compressor Shut off codes, not sure if universal across all models, but quite possibly:
(Check your repair manual or Measuring Value Block pop-up)
- 0 = Compressor ON
- 1 = Compressor OFF: Refrigerant Pressure too high (> 32 bar)
- 2 = compressor OFF: Basic setting not performed
- 3 = Compressor OFF: Refrigerant Pressure too low (< 2.0 bar)
- 5 = Compressor OFF: Engine Start Detection
- 6 = Compressor OFF: ECON Mode active
- 7 = Compressor OFF: A/C System / FAN OFF
- 8 = Compressor OFF: Outside Temperature too low (< 3.0 °C)
- 10 = Compressor OFF: Vehicle System Voltage too low (< 10.1 V)
- 11 = Compressor OFF: Engine Temperature too high (> 118 °C)
- 12 = Compressor OFF: Shut-Off requested by Engine Control
- 13 = Compressor OFF: Vehicle System Voltage too high (> 17 V)
- 14 = Compressor OFF: Evaporator Temperature too low
- 16 = Compressor OFF: Compressor Activation faulty
- 17 = Compressor OFF: No or implausible Signal Pressure Sensor
- 18 = Compressor OFF: Vehicle Speed Shut-Off
- 19 = Compressor OFF: Shut-Off requested by Central Electronics Control (Load Management)

 

 

Not sure what you mean when you write ECM? Engine ECU? That doesn't control the A/C.

Edited 12 July, 20223 yr by Breezy_Pete
Added shutoff codes

1 hour ago, Zaid said:

This happens during very cold climate too

 

I don't care, do you have a problem with the cooling fans or not?

Okay so 2 years back when i posted this question, i went ahead and changed the compressor wall(in some models clutch) without reading the answers here and the problem was resolved. 
 

Now 2 years later, this problem has started again and changing the compressor wall didn’t help too. We tried sensor swapping, no improvement. 
 

ac shut downs after 45 minutes or so, but first 45 minutes nice cooling. Technician says nothing wrong with fans as well. The ecu doesn’t show any errors.

 

 The temperature of the car was 145 degrees and we found out that the water pump bearing was faulty so changed that, still no luck. Please help