Help with P0530 - AC pressure sensor signal error code. C4 Lounge 1.6 THP.

[Simonjs]

Hi guys,

Has anyone had any experience of dealing with a P0530 code?

AC works fine at cold start but once the engine has warmed right up after say twenty minutes or so at some point the compressor stops running. The malfunction seems to happen more often when stuck in heavy traffic.

I've changed the pressure sensor and evaporator sensor for good measure but no luck yet.

[ozvtr]

Was the aircon running when you took the freeze frame data?

If it was running, 10BAR is low for an ambient temp of 32 degrees. Should be as high as 17BAR.

If the aircon was not running then the pressure is high. Should be about 7BAR if the entire system is at ambient temp (cool).

The fault says "inconsistent". Inconsistent with what I wonder?

Generally speaking, if the system runs fine when the ambient temp is cool, but cuts out when the temp gets hot, that indicates an over charge of refrigerant.

Could be the radiator fan is not working.

The pressure sensor indicating exactly 10BAR is a bit strange? Exactly 10BAR.

[Simonjs]

Thanks for the reply mate,

AC was switched on but it was no longer cooling air at the time of the screenshot it seems to shut off the compressor when that error code appears so only ambient temp/warmish air was blowing out of the vents.

I'm going to check the pressure when I first turn the car on when the car is cold and compare it with the pressure when the car is hot. If those values seem high maybe I'll consider bleeding a little bit of refrigerant off. Exactly 10 bar must have been a coincidence as the value does change and it has had a new pressure sensor fitted to eliminate that.

The front was smashed in and had extensive repairs so I believe the radiator fan is 'new' but maybe they threw in the cheapest aftermarket fan they could find. The fan does kick in at stage one and stage 2 seems to work. I've considered changing the fan resistor as maybe it is causing an intermittent fault and sometimes not switching on the fan at stage 2 when the engine is getting really hot.

[Simonjs]

With the engine cold at startup with the AC turned OFF I was getting 8.28 bar.

[Simonjs]

With the engine cold but running I switched on the AC and very quickly got 14.16 bar.

[Simonjs]

As usual from a cold engine start the AC was cooling pretty decently and I kept an eye on the pressure while driving and it fluctuated between 13.5-14, more towards 14 overall.

After about 15 minutes the AC noticeably stopped cooling air and pressure had dropped back to 9.32 bar when I assume the compressor isn't even running.

[Simonjs]

A few minutes after the AC stopped cooling I made a quick stop during which the engine was switched off for around 10 minutes. On starting the car again it felt like the AC was cooling very, very weakly but definitely cooling slightly with a reading of 12.90 bar.

In around 5 minutes I was home and the AC didn't seem to be cooling much if anything at all with a pressure of 10.81 bar.