2002 Jaguar S-type, 4.0, Auto, 105K Miles.


- Hello! New to this site and this is my first experience with a Jag.

Having an issue with no heat. When I turn the heat on it feels like its just fresh air blowing out of the vents. I flushed the heater core until the water ran clear, checked for leaks, coolant levels are ok.

First thing I checked was the DCCV. I even unplugged it so it would stay open. The hoses coming from it going to the heater core are hot when the heat is full blast, so I know the coolant is getting through and getting hot. But air blowing is cold???

I was told by a friend that an actuator may not be opening properly?
Any ideas would surely help, as the cold Michigan winter is right around the corner! Thanks!

 

Hi cdavis,
It sounds as if you need to replace the Heater Control Valve to cure your problem. This complaint crops up now and then and in most case is rectified by fitting a new Control Valve unit.
This Control Valve should be readily available from your nearest Jaguar agent.
Hope this is of assistance.
Regards,
Inver.

 

The heating system is actually simpler than it seems. Hot coolant in the heater core heats the air blowing over it.. All the mechanics are controlled by the climate control module. Sounds like the DCCV (Heater Control Valve) is working properly. Also, you ruled out the heater core, I assume by your post.. So, that leaves the control module..Have you tried adjusting the temperature to "high" and see if that changes things? If it does than I would start with the cabin temperature sensors. If it doesn't have you tried changing modes manually and notice how the air flow changes? These tests should tell you if the sensors, air diverters, or control module are the source of your problem.

 

Hi, Another thing to check is the outside temperature sensor. Is this reading correctly. If this is faulty, it can affect the interior temperature control. This sensor is cheap to and fairly easy to replace.
Regards,
Telfer.

 

Have you looked at replace the Heater Control Valve. Look down in the right front of the car and you will see it at the very bottle. Just follow the heater pipes to the front of the car. The heater valves are common problems on these cars with heating issues.

 

I have a spare ccm in black if you need me PM me if you do

 

He already checked that... The DCCV and the Heater Valve are one in the same....

 

Also check and replace the evap temp sensor. My climate was acting funny in my 02 and replaced it and no quirkes

 

Hey guys - thanks for all the replies.

A friend told me that it was an actuator that was incorrectly diverting the hot air somewhere else... He told me to look behind the glovebox and "I'd see 3 motors, about half the size of a roll of quarters... The very bottom one might be stuck, so use an allen wrench to manually move it...".... I'm new to Jags and couldnt locate any of these motors.

And about the sensors....Where are they located? I need to invest in a Hanes manual....

Thanks for all the replies

 

Oddly enough, it seems when I press the "auto" setting it always turns the A/C on.. not sure if thats normal.... I've cranked it to the HIGH setting and it still feels like its blowing the outside air in. I ordered a new Heater Control Valve because I got a good deal on it, so I figured it wouldnt hurt to replace it even if the older one isnt shot yet...

The outside Temperature sensor seems to be working fine, and reading accurately.

All the controls on the Climate Control Panel seem to be working correctly...blows in the right places, at the right level, just no heat.

Maybe a sensor could be off because when I hit AUTO it kicks the AC on... but when I adjust it manually shouldnt it blow at whatever temperature I set it at??

 

A secondary purpose of the a/c is to dehumidify the cabin air so it should kick on with the heat if you crank the temp up on auto.

If you crawl in the driver floor board on your back you will see two plugs on your left side one about 6" above the acelerator pedal and one higher towards the top it should be about the height of the bottom of the radio on the evap box. Insert a jewelers flat head to unclip the connector and then use the same screwdriver to unclip the sensor out of the box if the sensor is discolored replace it

 

Thanks alot, I'll check that in the morning...whats the name of this sensor/ whats the purpose? If it IS discolored, would that be the reason for no heat?

 

Check the sensors....they both seem to be okay and clean.

 

Did you spray them down with electronics cleaner or MAF cleaner?

Also have you tried to unplug the electrical connector from the DCCV and bring the car to operating tempratire to see if you have heat?

If you leave the connector unplugged and no heat you might have a bad dccv or the aux pump might be bad.

Have you followed the harness from the dccv and checked for chaffing? The 99-02 harness runs under the core support and chaffing can occur

 

I'm having the same problem, except I can get heat when I take it out of auto operation. As long as I set it for the hottest setting and use the fan control I get heat. Try and use auto and I get mildly cool air. It's my wife's car and she didn't understand how to get warm air until I started messing with it. My best guess would be a sensor, but I'm not familiar with climate control systems. What should Ibe looking for? Also even with it on single mode operation(dual mode off) the passenger side air feels a bit warmer than the driver's side. What could cause this? Thanks.

 

Check the sensor above the ignition key made sure it's clean it's the cabin ambient temp sensor

 

Ok, I'll give that a check. Thanks!

 

Hi Torrid,
which engine and year ?

Giacomo

 

I've got the 2000 4.0. It looks like it is the DCCV, only I can't find the part by this name when looking online other than DIYs. I'm getting warm air on the passenger side and cold or freezing air on the driver's side. Would this be the right part if it is the DCCV? Thanks.

http://www.thepartsbin.com/catalog/?...365+4294952375

 

The DCCV is sometimes called a heater control valve. That's how it's listed on Rockauto. Be aware you will save money by getting the Lincoln LS part.
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