Hey everyone,
I own a 2003 jaguar s type 3.0 L and I am currently having trouble with the CCM. The code I have is U2518-missing message from electronic air temperature control. I replaced the DCCV and cleaned all the sensors in the car as well as charged the system. Upon activating the AC button the compressor does not turn on. Please help if you can.

 

Check the pressures. It's disabled if any is out of range.

 

I'm not well versed in the U series messages, but that could be caused by something as simple as a blown fuse. Don't scare yourself that the only possible explanation is something expensive, such as a failed module.

Work through this guide:

https://www.jaguarforums.com/forum/s...ol-how-185002/


Specifically, test your new DCCV as detailed in post #2. If you try to tell me it must be good because it's brand new, I shall hack your phone and make it play Justin Bieber songs on an uninterruptible loop until you relent. The same DCCV test also checks fuses, so please don't skip it.

After that, run the tests in post #5, since your AC compressor is not engaging and you have no cooling. Once again, this could be as simple as a blown fuse. It's also possible your refrigerant has leaked down again, perhaps from a service valve that didn't seal completely. Don't automatically rule out low refrigerant because it was just serviced. Work through the guide in order and it should lead you to a correct diagnosis.

Please keep us posted and let us know what you find.

 

I have checked all the fuses no blown fuse, I pulled the CCM and checked for burnt traces and no burns or bad diodes.
I just recently got around to testing the compressor with a power probe by disconnecting the compressor and shooting power to the compressor with the car running and to my discovery no power to compressor. So I think I have found my culprit and will replace it, test it and repost.

 

I'm having trouble following your test logic. Are you saying you jumpered power to the compressor clutch but it still won't engage? I initially thought so, but then you mentioned finding "no power to the compressor". I'm officially confused.

In the troubleshooting guide, post #5 has a quick method to test the clutch from the relay panel. You don't have to crawl underneath or disconnect anything, other than pulling an easily accessible relay. It tests not only the clutch, but all associated wiring, too.

 

I used a power probe to try and power/engage the clutch and had no results. I did try probing from the engine compartment fuse box , fuse#8 and had no power. That's why I went straight to the clutch/compressor to give it power. My new DCCV is good and in working order, I have checked all the fuses associated and not associated and all was good.

 

After testing the clutch and compressor, I found there to be no power to the clutch. I replaced the compressor with a UAC complete compressor kit and now ice cold.