ANDY-C
04-06-2023, 10:10 PM
Hi all, im hoping someone can help point me in the right direction. The car is relatively new to me - March 2023. Its a 2011 2.0 tdi manual with the CAHA engine the car has done 153k. I ve been working through a few issues and doing the cambelt, waterpump, thermotsat etc. The air con has never worked properly and the issue is as follows - no fault codes apart from air quality sensor. The car only has a single cooling fan (factory spec) the fan only works intermittently - when it does work there are only 4v going to the fan from the fan controller - assume speed 1. Now when the fan works the air con will kick in - the measuring block info (Xtool VAG401 OBD code reader not VCDS) shows absolute pressure rise from a resting 70psi which rises to 185psi, however as soon as it hits 185 psi the air con knocks off but the radiator fan continues to run and the absolute pressure returns to around 98psi. I had the car re-gassed as it was down to a about 50% gas volume but the issues remain. Now i'm thinking there may be a couple of issues - one to do with the fan only switch on intermitentaly and secondly the air con switching off when the pressure his 185psi. However with no fault codes i'm struggling where to start - could the fan issue be a faulty relay and if so where would it be - i cant find any info on where it would be, could the air con knocking off at 185 psi be the control solenoid on the side of the pump or possibly the sensor on the side of the air con rad? Any help or experience of similar issues would be much appreciated. i'm loathed to take it to a garage as they will most likely just start replacing parts until they stumble across the faulty one. As the system works and has no leaks i'm thinking it must just be a sensor but i'm not sure where to start. Thanks Andy