I know there are a hundred threads on the DCCV valve but I have not seen any with the same symptoms as mine. I have a 2000 S-Type with the 3.0 V6, From the drivers side vent it will blow cold air, the passenger side vents will be luke warm and the two vents in the rear seat (front center console) will blow very hot. I have replaced the dccv and the problem still persists any ideas would be greatly appreciated.

 

Could be the blend motors? And/or the module.

 

Unplug the DCCV and see if the center wire in the harness connector is POSITIVE and the outer wires are GROUND (EARTH) with the temp set to LOW, A/C ON.


The climate control module provides the EARTH to CLOSE the valves and the center wire should be 'hot' all the time through a fuse. (key on)


I use a small light bulb with wires to check the power to the harness connector. The CCMs have a copper trace that can burn when the DCCV draws too much current.


The Climate control module can usually be repaired.


Sometimes the DCCV sticks in the OPEN or CLOSED position regardless of the CCM settings.



bob

 

Thanks for the quick replies. I checked the DCCV plug with a volt meter, the pin on the drivers side read 0 volts the center pin read 13.4 volts and the right side pin was fluctuating between 4 and 5 volts, I also examined the CCM and didn't notice any burns on the board itself since my S-Type in a 2000 model year I wasn't sure if the CCM issue with the 03 and up could happen to mine. As far as the blend doors, I'm not sure if the S-type has a blend door for a/c and heat? Thanks again its greatly appreciated!

 

You need to check between the RED wire and the Brown/Green for the Driver's side and the RED and Brown/Blue for the passenger side.


The RED will be battery voltage and the BG and BU wires should be EARTH when the A/C is set to COLD!!


bob

 

Interesting problem. Let's confirm your new DCCV is working properly. See post #2 here for instructions. If you insist the DCCV is good because it is new, I shall chuckle quietly to myself while waiting for you to test it anyway:

https://www.jaguarforums.com/forum/s...2/#post1714570

Even if the valve itself is fine, it may be getting an incorrect command. The test given above will confirm the valve is getting the correct command and responding properly by shutting off all heat. Fix the known problems first. I'm not sure from which side the rear duct gets its air, but since you've already noticed the passenger side is warmer, that's a problem. Take care of that and it may also fix the rear duct temperature.

Have you tried driving the selected temperature down until LO is displayed? This puts the system in manual mode and bypasses many of the auto inputs.

 

I usually dont use the "auto" mode, I prefer the manual "lo" setting. When I use the volt meter and connect the center to the passenger side prong on the DCCV plug I read 12.4 Volts, when I connect the center to the drivers side prong I read between 3 and 7 volts.

 

Sounds like the circuit is high resistance. Could be a harness issue or the CCM copper trace burnt and not supplying proper ground to the DCCV solenoid.


A faulty CCM semiconductor for the driver's solenoid can also be the cause.


The DCCV actuator will likely not close with the low voltage supplied.


If you get the same 3 to 7 volts at the back of the CCM connector, the CCM will be the logical fault.


Back-probe the CCM to verify???? Fascia Connector (FC27-06 NG Brown/Green) is the output to the DCCV Driver's solenoid.



bob

 

I will check the ccm outputs this weekend. Thank you so much for your help. I will report back once I prove the CCM. I've also gotta find a three wire connector for the DCCV as mine is now broken.

 

The early Lincoln LS used the same 5 pipe DCCV so a Ford dealer might help????


bob

 

See attached for replacement connectors under appropriate section.

 

Thank you all so much! Sorry for the lack of reply I finally got a chance to check the control unit out it is working fine. Has to be a wiring issue as I am starting to see other issues with the car. The pigtail isn't in the book and the ford dealer is telling me I need to buy a complete new harness. I hate to say it but it might be time to give the old Jag up and look for a replacement.

 

Scrap car places (wreckers) will be able to supply (or DIY if they let you).

Your overall trouble sounds a bit like a bad battery...