G-8VXWWTRHPN AC Issue, Compressor Shut-off From ECM (Code 12) - VWWatercooled Australia

Announcement

Collapse
1 of 2 < >

Email Notifications Failing (mostly Telstra)

Hello everyone. Seems there is an issue with Telstra (possible others) blocking email from our server. If you are trying to sign up I would suggest a different email if possible. If you're trying to reset your password and it fails please use the Contact Us page:
2 of 2 < >

Welcome to the new look VWWatercooled

After much work and little sleep there is a new version of the forums running on more powerful and recent hardware as well as an upgraded software platform.

Things are mostly the same, but some things are a little different. We will be learning together, so please post questions (and answers if you've worked things out) in the help thread.

The new forum software is an upgraded version of what came before, it's mostly the same but also a little different. Hopefully easier to use and more stable than before. We are learning together here, so please be patient. If you have questions, please post them here. If you have worked something out and can provide an answer,
See more
See less

AC Issue, Compressor Shut-off From ECM (Code 12)

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • AC Issue, Compressor Shut-off From ECM (Code 12)

    I've been banging my head against a wall with this one. Ever since owning my 2008 Mk5 1.9L TDI Golf. I've never been able to figure out why the AC does not blow cold air. More specifically why the ECM is commanding the compressor to not engage.

    I've scanned the car and there are no faults in the Engine or HVAC Module, All the sensors are working and reading within expected range (Replaced the N280 annd G65) No leaks in the AC System and been Regased.

    Compressor and Radiatior fans confirmed working after manually bypassing the ECM and engaging the N280 Solenoid / hard wiring the fans; cold air came out. Fuses checked.

    So I'm 99% sure the ECM is receiving something it's not happy about and is to my understanding "load shedding" systems. But unfortunately I haven't been able to find any information as to what causes it to spit the dummy! Other than a possible vacuum leak in the brake system. But I have isolated that and believe there's no issue there. again nothing found on live scans through OBDeleven.

    I've literally searched for hours and hours going the SSP's, Wiring diagrams, Forums and random youtube vidoes spoken in russian trying to get to the bottom of it. Can someone please help!

    Thank you!

  • #2
    The compressor is probably blown. Mine never gave any codes, but a new compressor resolved it.
    MK4 GTI - Sold
    MK5 Jetta Turbo - Sold
    MK5 Jetta 2.Slow - Until it dies.

    Comment


    • #3
      Thanks for the reply mate. Was your compressor seized and hard to rotate when replaced? I took the belt off of mine and it spins freely. I just don't understand how the ECM knows to shutdown the system and throws out the compressor shutoff code 12 instantaneously when the AC button is pressed. I really feel like there is a wiring issue that isn't showing up?

      Comment


      • #4
        Furthermore i've found this in the 1.9L TDI SSP from VW:

        Air conditioner compressor cut-off To reduce engine load, the engine control unit switches theair conditioner compressor off in the following conditions:
        - after every starting cycle (for approx. 6 seconds)
        - under rapid acceleration from the bottom end of the revband
        - at coolant temperatures in excess of +120°C
        - in the emergency running program.

        The investigation and head banging continues...

        Comment

        Working...
        X