Folks,


My wife was 70 miles into a 125 mile trip (to see our kids) with the A/C running when suddenly the air stared coming out quite warm. It's as if you selected full heat. This happens in all modes, A/C or not, all the time. No codes or warnings came on, the coolant is not low and the engine runs smooth. What gives? Have you seen this before? I have seen something similar on a Ford with vacuum motors on the ventilation system and a vacuum line break or come loose. Does this car use vacuum motors or electrical solenoids? Please help, it in the 80's in Louisiana and no time for heat! The car has 82,355 miles on it.
Thanks in advance for your help.

 

It could be a number of things from the DCCV to the Climate Control Module. See if this link helps you troubleshoot the problem.

Link - JaguarClimateControl.com

 

mine does same but caused by actuator for heater doors sticking on .. or off. about to attack because winter is coming in Australia ... yes it gets down to 7 c.....

 

I had this problem about 3 years ago on my 2006 STR. It was a known fault with the wiring

 

It's probably your DCCV (dual climate control valve) and possibly a damaged CCM (climate control module - control in your dash). I had the same symptoms.

Try this for a potential DIY solution:
https://www.jaguarforums.com/forum/s...t-fault-94932/

See comment #25 for a summary of how I fixed mine myself.

 

See this: https://www.jaguarforums.com/forum/s...t-fault-94932/

I was led down the actuator/motor or vent flap being stuck but it wasn't that at all (in spite of DTC code specifically stating the vent actuator/motor was the problem) - it was the DCCV and CCM. Not saying for sure that yours is the same situation as mine - just a possibility to consider. My car doesn't even have the actuator that was referred to by the DTC, but I think yours does...

 

Folks,


Sorry to be so long, my wife and I left 6th of May for a 3 ½ week vacation and have been busy with work since. I looked on the ( http://jaguarclimatecontrol.com) site and diagnosed per their instructions and e-mailed them. They want me to send in the CCM for checking and rebuild. I have not tested the DCCV unit as the electrical connection & hoses look good. The coolant level is full and there are no leaks in the system. After reading more on this forum I pulled the CCM out and took the circuit board out. I found a shorted run, see picture- center run that is copper colored. Does this mean my DCCV is bad? What caused the burned spot on the circuit board? I can solder, sorta', and am willing to take a stab at fixing the board.

 

Hi Mudman,
That certainly looks a lot like what happened to me - though I can't remember exactly which pin/trace. In my case, the DCCV failed which caused too much current on the CCM board, burning the trace between the pin and the Siemens BSP 78 chip on the board. That chip has overcurrent protection, protecting the rest of the board but leaving the trace leading to it vulnerable to overcurrent and burn-out. Kinda dumb design.
My fix: I soldered a wire with a 2A fuse from the pin to the destination pin on the Siemens BSP 78 chip on the board, marked as IC7 (your board may be different). That effectively bypasses the burned and vulnerable trace. Next time the DCCV fails causing overcurrent, the fuse should blow and would simply need to be replaced.
Then I replaced the DCCV - a pretty simple process taking about 20 minutes. You just need to be careful draining the existing coolant, replacing it and bleeding the system properly - but no big deal.
There's more info in this post:
DTC B1265 Cold Air Bypass Actuator Motor Drive Circuit Fault
You can source a LINCOLN/Bosch DCCV on ebay or from a dealer and save some more $$.

 

Mudman - some more info: in my case there was no visible damage to the DCCV. The DCCV can mechanically fail, coolant can get into the DCCV electricals and short the circuit internally, causing overcurrent back to the CCM board which then results in the the burned trace on the CCM. I'd say chances are very good that your DCCV needs to be replaced and you need to fix that trace. I believe that the guys at http://jaguarclimatecontrol.comuse something other than a fuse on the replacement wire bypassing the trace but effectively it does the same thing. Sending it to them is a good plan if you don't want to do a DIY fix.

 

It is normally the DCCV that takes out the CCM so whether you go the DIY route or use Jaguarclimatecontrol you should replace the valve.

chtp66 20mins is impressive!

 

Folks,


I said no coolant leak and I meant it, but...for months I've smelled a faint odor of burned coolant when walking by the car with the engine off and hot. I've checked the coolant and have not noticed a drop in the level, could this be a miniscule leak that is evaporating/burning off and maybe a sign the DCCV heater valve is going out?
Just thinking...

 

Could be... the burned CCM trace and the heat on constantly are probably the best indications that the DCCV has already failed.

In my case, the DCCV had a small coolant leak internally (not really visible externally) that shorted the electricals within the DCCV and because the electricals internally were shorted the DCCV wouldn't activate to cooling position, and aslo sent overcurrent to the CCM which burned the trace. Sounds like you have exactly the same symptoms.

 

Mudman,
I found the DCCV replacement I used: The Ford/Motorcraft part # for the 3 hose (2003+) Lincoln LS DCCV is YG378. Amazon stocks it: for $98

 

Folks,


I am waiting on a new DCCV heater valve and two new heater hoses. The DCCV was ordered from RockAuto for $96 including shipping (yep I ordered a Ford YG378) and had to get the heater hoses from PartsGeek ($47 & $46 plus shipping). Once they come in, and I get the time, I'll be able to test my repair of the CCM board...and hopefully have cold A/C 'cause it's getting warm in Louisiana!


P.S. Thanks for all the input, this forum is a blessing for some one new to Jaguars like me!

 

Guys,


Well the parts came in and I finally found the time to put in the new DCCV heater valve and new heater hoses (for good measure). I used the Ford (Motorcraft actually) YG-378; it was identical to the OEM DCCV and is a little cheaper than the Jag DCCV (thru online suppliers). I replaced the heater hoses (from aluminum tubes on fender to DCCV) because I like to change hoses preventively once they are 7-8 years old, especially if they are hard to get at...like the connections at the DCCV heater valve. Now the A/C is cold and my wife is happy.
Thanks again for the tips, such as soldering the shorted run on the CCM board- this tip saved $250 and several days of shipping, and all the advice.