2000 S type 4.0

AC has always worked fantastic….driving on highway and all of sudden got blast of hot air with AC on….next day checked the high and low pressure lines/freon... was good, compressor working….blows ice cold until car warms up, Read a lot of helpful threads on here so I felt i should change the DCCV, did that and still same problem, so then replaced CCM and still getting cold AC on start up and hot air when car warms up. I'm thinking I possibly got a defective new DCCV? I'll try putting a new Bosch one in this week (auto parts store said they will replace the one I bought and suggested I use a Bosch this time).

When the AC is on for over 5 minutes and blowing hot air, the heater hoses going into heater core are very hot. My questions are:

If I put manual shut off valves inline on the two intake hoses to heater core and manually stopped the flow of hot water to core…would this be a good (primitive) way of checking if my DCCV is still bad? I would assume I should get cold AC? If so... can someone tell me which hoses are the inlet ones to heater core (there are two on top and one on bottom). I figure two inlet and one outlet?

Also….could this be a blend door problem? Is there actually an AC/Heat blend door…or does the DCCV basically control that type of function (heat/cold regulation)?

Thanks, any advice appreciated.

 

The DCCV can be fickle, as you are finding out.

I did both mine recently and both cars had different ssiues, and not anything like yours.

My findings on the "up to" X202 models, so our cars being X200, it fits, is that the centre wire of the DCCV plug is 12v LIVE, and that comes from fuse #1 in the engine bay fuse box.

NOW, without that 12v the DCCV defaults to FULL ON, and the system cannot do anything about it, full stop.

The pipes you asked about are the 2 top are SUPPLY, and the lower is return.

Inside the car, on the dash panel, somewhere near your RIGHT knee (LHD car) is a small grille aperture. Inside that aperture is the "sniffer" for the system, and it gets clogged with dust, and cannot read, so havoc arrives in the system.

Maybe more, but that is my understanding after sorting "her" car. when the new Bosch tap still had NO control over heat. Replaced the fuse, SWEET, but her tap was JAMMED shut, so she was cold, new tap, she was toooooo hot, bugga, fuse fixed it, happy wife, happy wife HAHA.

 

I heard that a bad or low battery can cause electrical component to malfunction

 

Yes. Several people have reported bad DCCV's right out of the box. But do a few electrical checks before you condemn the second DCCV.

I would just pinch off the heater hoses if you want a temporary water shut off. Very little room to work and you don't want to cut and splice heater hoses.
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I am going to go through those electrical tests, and then if it looks like the DCCV is bad, I'm going to replace it with a Bosch part….the parts store said they will replace the one we installed. I'll just pay the difference in part cost. Hopefully this will do the trick. Will advise…..

 

OE ones are Bosch, and stick or leak after a few years. It would be good to find a non-Bosch that was reliable instead of the unreliable Bosch one.

 

I have 2000 S-Type but it is a 3.0 not 4.0 but I will provide a few links that might help.

Link to DCCV Change JagRepair.com - Jaguar Repair Information Resource

Link to A/C Temp Sensor JagRepair.com - Jaguar Repair Information Resource

Link to 2000 S-Type electrical http://www.jagrepair.com/images/Auto...01999.25en.pdf

and go to page 101 for Climate Control System. The oneline does not differentiate between 3.0 & 4.0 so I assume they are the same.

I would be looking at the fuse for the DCCV (check with volt meter) and also clean the sensors.

 

Thanks guys, I weill go tomorrow to parts guy….I'm not sure if it was Bosch or not but when we purchased the one we put in car it was substantially less in $ than another one he recommended….and he did make a comment that we should use the more expensive one…i figured that was just BS but who knows? I will let you guys know what brand is his upgraded one… I believe the difference in price was like $85 for the one I bought and installed or $160 for better one? Hopefully will tackle everything by Saturday…and advise…. Otherwise I'll be going to a plumbing supply store for two manual heater valves.

 

I have one on my page that I bought for my car 2000 3.0 but did not use. It is a Motorcroft YG-355 Not sure if it is the same on the 4.0

Link JagRepair.com - Jaguar Repair Information Resource It is the last item on the page.

 

So it appears it was a faulty DCCV right out of the box….we used a Bosch as a replacement…it was the only other brand available over the counter locally for me…it was about double the price of the cheaper unit. It even looked different. The Ac is blowing ice cold again. My next step i was going to order two manual heater shut off valves from Summit Racing….glad i didn't have to go that route. Thanks again to all of you for all the advice this forum has supplied me with. The replacement of the CCM was unnecessary, we checked both and they are all good. So if anyone needs one for a 2000 S-type, let me know…I paid $50 from a parts place on ebay…I would sell it for $30 plus shipping if anyone needs it. Also I'm going to re-list the car on ebay in the coming weeks…in case anyone is interested. I'm going to need to use the car another week or so, taking it on a 600 mile trip next week.

 

ok, possibly spoke to soon. It seemed ice cold for two days, then today i noticed it being intermittent. I checked the hoses going into heater core. there are three, the one on bottom is hot and the one on top left is hot, the one on right seemed cooler. When you look at a photo of a heater core on the parts sites it seems one on top and one on bottom go to opposite sides of bottom of heater core and the other top one goes to top middle of heater core. Is the top middle one the outlet? and does the coolant flow of heater core go from bottom to top? or maybe I'm just looking at a part photo in the wrong position. I am thinking about bypassing the two inlet ones with manual shut off valves to see what happens when I cut off flow to heater core. Also one of the top heater top horse into firewall seems to drop down and split off, one split going back towards DCCV and the other one running towards left side of car….where would that one be going? and is that the outlet hose? thanks for any help. I am also going to try and bleed system a few more times. My next step if it seems DCCV keeps allowing water flow is maybe sensors??? So far two DCV and one CCM…..defineatly working a little better now with new DCCV but was getting intermittent hot air…. also what about a blend door actuator? IS there one for heater to AC box?? and if so where specifically is that one located? thank you

 

Ok, I ended up installing two 5/8 " nipple on each end, "four seasons" brand, manual hvac shut off valves in line just above the dccv and a few inches before it goes into the metal pipes going towards the heater core. A/C works well….took me about 45 minutes because of tight fit…i also recommend doing it when car is cold. I know this is a cheat fix, but I wanted some cold A/C this week. If i don't figure out the DCCV by winter, all I have to do is open the flow of hot water by twisting the valves to open. Its also a great safety valve in case of any future heater core leaks. I cut the hose cleanly just before the click on fitting that goes into the metal heater pipes. It made it easy to install the valve on that end, tightened up with a use clamp off the car…then slipped the other end of valve into the hose going towards DCCV and tightened with hose clamp (this end was a little harder to get my hands down to tighten clamp). then just clipped fitting end of hose into metal pipe hose going toward heater core (remember to watch that the two rubber o-rings in each fitting are still there when re-clicking the connections) … i will try too add some photos tomorrow. Cost of two valves were $24 total, and you need 4 hose clamps. I was thinking about first try to do the valves on the hoses coming out of firewall, but it seemed to tight a fit. Of course now its probably more of just AC (when valve is closed) or heat (when valve is open), not a climate control temp…..unless DCCV starts working in winter.

 

Here is a photo of the two valves i put in, just above the DCCV. The second valve is right below the top one…hard to see in photo. They are basic twist on/off valves, made by Four Seasons company, which I think is owned by Standard Motor Products.

 

Check the wiring behind the bumper. When the DCCV goes it draws a lot of current and the wiring is cheap and can bubble. You get an intermittent connect sometimes instead of a complete break.

 

Impressive, I used two small pairs of vise grips and cable ties.

 

Yes, I tested it with vice grips, but pretty much knew my problem was still hot water going into heater core. Also was given wrong info by local mechanic that told me only one heater hose was an inlet…. on 2000 S type, two hoses are inlets, the top right and one below going into firewall…the top left is an outlet…i pretty much knew this by feeling the temp of hoses, but also confirmed it by a schematic of heater system that I found online.

As far as the bumper wires, where in bumper are the wires to DCCV?

 

Thanks for your explanation and photos of your fix.

I am looking to do what you did after I have the CCM tested. In my Jag the DCCV has been replaced and the CCM does not show any obvious signs of burn marks.

After you put in the shut off valves. I would like to know. Have you had any overheating or air blocks in the system? Or any issues relating to this fix worth mentioning.

Thank you
Paul

 

The fix has been great, no overheating or air blocks.

 

fix was easy and pretty quick…. make sure the car is cold when you do it so you don't get burned by hot antifreeze.. good luck