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2011 Jetta TDI with AC not working... I'm lost on what to check or do.

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  • 2011 Jetta TDI with AC not working... I'm lost on what to check or do.

    I have a 2011 jetta tdi and no AC. I've read that some of the compressors on the jetta are clutch less not sure if my compressor is a clutch less or not but if it is a clutch then the clutch turns at all times whether AC on or not. You never hear anything different from the compressor kicking in or anything just spins. The fans are on and running. I connected gauges and had zero pressure on both low and high. I attempted to add 134A refrigerant but it never pulled a whole can of 12 ounces.... maybe a thrid of the can went in. When I reconnected the gauges Low side was 100 and High side was 60... started the car and turned on AC and no change in gauges. I don't know why VW doesn't label Fuse Panel covers as to what is what to try and check fuses or jump the compressor but couldn't find anything in manual or on line as to how to do it. Any help is greatly appreciated. This is my daughter's first car we bought her and really don't have the money to send to the shop at this time so was hoping I could figure it out.

    1.Could it be a pressure switch bad?
    2.Bad expansion valve?
    3. I did not pull a vacuum before adding refrigerant...could it have air trapped?
    4. Bad compressor ?
    5. Bad compressor control valve?

  • #2
    3,4 and 5 are the more likely. We have run into bad control valves fairly often on VW.
    If it is clutchless then there will be no relay to jump.
    Why are you adding cans not through the gauge manifold? Do you have the manifold and tooling to do A/C or are you just taking stabs at it.
    When you first checked you said it was at zero, That means it has all leaked out and taken some of the oil with it. Until you fix the leak, the rest is academic.
    It is likely to need either 4 or 5 but until the leak is solved there is no point replacing these parts.
    If you do not have the tools, your are going to need someone who does.
    You need to leak check 1st, then remove and check out the compressor, drain the oil and measure how much was in it, then refill with the correct amount.
    Very likely there are multiple problems, one is where did the refrigerant that came in the system leak out, another is why the compressor is not compressing when there is pressure? Could be as simple as the system detects there isn't enough in the system. It could be the compressor seized and the break-a-way in the pulley has snapped.
    These systems are NOT DIY friendly, and not the system to try and learn A/C on.
    Not the news I am sure you were hoping for, but you could throw a lot of parts at it, it may work for awhile, and then be right back where you are now. It is VERY unlikely that you can throw parts at the problem and throw all the right parts to fix the problem on the 1st attempt. Each failure will like damage more of the system, and even some of the new parts. It can get quite expensive and aggravating.


    • #3
      Looking on the parts suppliers like RockAuto can be a good way to see what you have. It also can be confusing because they "mis label" things. For example they list a "compressor with clutch" but there is no clutch as evidenced by no wires or connector at the pulley.
      Looking there I can see you have a clutchless variable displacement compressor, that the safety system uses a pressure transducer ( NOT a SWITCH).
      The pressure transducer is connected to control that looks at several inputs and returns an output based on what it "sees".
      It is quite possible it looks at the high side pressure, and the air and heater box temps, then says "there isn't enough pressure with the system off for there to be enough refrigerant in the system. 60 psi high side is below ambient temp ergo not enough in the system to even turn on.
      You have to sort out the leak before going any further. If it were mine I'd force enough refrigerant or nitrogen into the system to pressurize to ambient pressure then use a sniffer to find the leak, then suck out the refrigerant and repair the leak, pull the compressor and inspect, if good, would just change the electric valve on the compressor while out, too cheap not to, dump and refill the oil and evacuate and re charge. Going over the whole system with the sniffer allows a visual inspection of the whole system at the same time.
      All that requires a recovery machine, sniffer, a set of gauges, may be a gasket kit for the compressor and the knowledge of what to look for on the compressor once that is done, refill and I can trouble shoot any remaining problems with system performance if any.

      If you don't have the equipment you can't do that. Even with the equipment it is an expensive undertaking.
      Long gone are the days that you can throw a can in the system and if lucky have cool air for the season.
      Cheapest way out if you can't do all the diagnostics in one shot is to pay someone who can.
      I said it before but will repeat THERE IS NOTHING TO "JUMP" ON THESE SYSTEMS AND DOING SO RISKS COMPUTER MODULES that will cost more than paying for proper diagnostic.
      Transducer often run on 5 volts or less, putting 12 into that system can destroy expensive parts


      • #4
        Thanks guys! I failed to say that my brother is certified in residential HVAC tech but no longer performs just for family and friends. He has the the equipment to pull refrigerant and a vacuum pump along with gauges which I purchased the adaptors for hoses. He has a sniffer but it is broken so what I was attempting to do was add so refrigerant " for he doesn't have any nitrogen either" with UV dye and see if I could find the leak and then pull refrigerant. After adding I noticed the schrader valve at the low side bubbling some dye. My hopes is this is where the leak came from and I can replace. with the system not circulating not sure I could tell but I could not see any other area of with the UV dye with my light. When I bought the car we took it to MF Auto to run a diagnostic of the car with there VAG/VAS below were the faults found on the AC.....

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        • #5
          I know I should have done the vacuum first to see if there were any leaks. If it holds vacuum and no leaks then I'm going to go with the control valve in hopes that fixes it. I will update after I do it.


          • #6
            Well those codes have a date of 2017, so unless you have been without A/C since then, I wouldn't worry about them. The code is for the high pressure A/C sensor.
            Vacuum is at best 14.7 psi, so while if the system leaks at that pressure, then it will likely leak under positive pressure. If it doesn't leak under vacuum, it is not proof positive that it will not leak under pressure.
            How long has the system been in-op?


            • #7
              Hi and welcome here: By chance plead IDK this work or on in person. I'll just suggests you do evacuate, hold that and put back by weight should be listed on a sticker.

              IDK what's availed to you to count what came out. It's not likely right so all bets off now. It's possible it would behave at least a while if an unfound leak how fast if that worked.

              If no serious leaks it just might snap out of this? I'd give that a try at the risk of losing that refrigerant. It just might need a high end scanner/device with paid for programs to get this going with existing items. That would be luck of if not needed?

              Sorry for lack of more I lost my person and all those if so would do that I'm done investing in more it would never pay off or break even. Your call I can't see how that would hurt anything there are always some risks it does cause harm??

              Other is stop and find the right shop/person and just pay for it all or just get same to do a full diagnosis and do as much of it as practical for you,
              MetroWest, Boston


              • #8
                I want to thank you guys again for the knowledge you are willing to share. Forums such as this has help so many people not only with time but money.

                Not sure how long it's the Jetta AC has been like this. We bought the car the first of April of 2023. The guy I bought it from said it worked the summer before "2022" but wasn't cold by the end of the summer so he added refrigerant but it didn't help and it quit blowing cold all together and thought he most likely over filled it. He was very detail in telling us what known issues the car had which was minor so I felt he was being truthful but now think he got one over on me. We took the car to the shop on April 13th 2023 to have the Shifter looked at because it would only take reverse after going into drive ... found it had a shifter linkage broken.. which he the guy explained to us. I did not catch the dates on the codes were from 2017... below is snap shot of the top of the report that shows April 13th which I read and thought everything below it was from this scan I was having done So I guess the shop didn't do a complete scan for the codes??? It just says HVAC status Malfunction 0010.... along with others having the same 0010 malfunction. I attached the complete report as a attachment that they gave me. If you have time to review... my guess is that you'll say they never ran a full scan for codes.

                It was $427 for them to find issue with shifter "NOT TO FIX" and full inspection. The shop did call to give me a updates and said that they did not look into the AC that much due to the cost to fix shifter was going to be high and I'd probably want to wait on the AC. When I dropped the car off I asked them also see what it would cost to fix the AC also. The shifter replacement alone was going to cost $1400. I just went and picked up the car and brought it home because I could not afford $1400 more. I replaced shifter myself ... found used shifter on ebay $225. I understand that the VW AC system is a very elaborate system that not the average Joe "me" needs to mess with but I've been able to fix simple things like the replacing a expansion valve on my wife's Altima so I wanted to take a stab at it because at this time can not pay what I'm afraid it would cost in the shop for the said worst case on AC be about $2200.

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                • #9
                  Only thing known for certain is the refrigerant had leaked out. Start by sorting that out. If you have too put one can in to get the pressure up. Then run a sniffer around the system and try find the leak.