I'm getting cold air out of the driver's side vents, but warm air out of the passenger side & rear passenger vents.

Only if I set the A/C to auto will the passenger vents blow a little bit cooler, but not by much.

This is happening now, but I hadn't driven the car since May. In May, I noticed a small amount of coolant collecting on the ground, under the front p/s engine compartment. I traced it to the DCCV. It only leaked a small amount. It was during a change in weather from hot to chilly. I thought maybe a hose was just oozing because of the weather change. I topped off the coolant. After that, I didn't notice any more leakage.

Can the earlier leak from the DCCV be connected to the warm air I'm experiencing out the passenger vents now?

What are typical troubleshooting steps for such a problem?

 

Hi
I think you have to fill up the A/C with gas (freon). Same think hapent to my STR but after i filled with gas, everything is ok. Mike

 

Funny you should ask:

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


The symptoms sound like like a bad DCCV. Run the troubleshooting steps in post #2 at the link above to be sure.

 

Thanks.

I'll read up on that thread & go from there.

 

I never got to troubleshooting this problem yet.

Today, I was driving with the A/C on (driver's dash vents opened, passenger dash vents closed). I had the recirculation feature on at the climate control panel. At one point, the recirculation feature shut off by itself. It had never done that before. I pushed the button on the control panel to turn it back on & it didn't shut off by itself for the rest of the drive.

Would this issue with the warm air out of the passenger vents, & now the recirculation feature acting up, be something wrong with the climate control panel? Or, should I suspect something else?

 

By chance was today's trip longer than normal? Working from memory, but I think that is normal behavior. When recirc is manually selected, it goes back to fresh air after a certain time limit. If you hold the recirc button for 2 or more seconds, it overrides the timer until the next startup.

 

Shortish push: recirc for a while (and mine single-beeps). Long push: indefinite recirc (unless you do such as defrost or something) (and mine double-beeps).

 

It was only about a 15 mile drive. I'd never noticed the recirc shutting off by itself before, or any beeps when pressing the button... but I'll be darned, it does beep 2x if I hold down the recirc button! This is 5th summer I've driven it, & never noticed that before! Lol.

Does this have a climate control diagnostic feature like I've read Lincoln LS's & other model Jags have?

 

Good question. I don't think so but am not positive. Maybe somebody else will chime in.

Regardless, you may be getting sidetracked worrying about the system doors and any diagnostics. There is no door that controls air being routed to the left or right side. Airflow is always the same on each side. Temp control for each side is via the two valves in the DCCV and the corresponding side of the split heater core.

Scroll up to post #3 and follow the instructions, specifically the ones to test the DCCV. Your symptoms sound exactly like a jammed valve in the DCCV. Don't just shotgun it. Follow those simple steps to make sure.

 

I guess diagnostics can't be initiated at the panel. I just read in the Jaguar Tech Training Manual linked in the epic troubleshooting thread. Says about the S-Type... "All diagnostics can only be carried out using WDS. No separate panel diagnostics are provided".

I was just so excited learning that the recirc button has a timer option, I thought maybe the panel had a diagnostic feature. Lol.

I started reading that epic thread to get familiarized with what must be done. I just haven't checked anything on the car yet. Today, I only turned the heater on & it was blowing real hot out the passenger side, but not as hot on the driver's side.

 

I put thermometer in vents...

83° outside... set at Auto/65° w/recirc on, parked at idle... 66° driver's side; 76° passenger side.

While driving... same settings... 76° driver's side; 83° passenger side.

While driving... set manual Lo with recirc on... 79° driver's side; 83° passenger side.

 

I was expecting more like ice cold.

 

Good so far through the end of that sentence.

And those readings don't help much at all. They show something isn't right, but that's about it. We knew that from your first post.

It's 76F where I am now.
My parents got married in 1943.
I wear size 13W shoes.

What does any of that have to do with anything? It's just more examples of factually correct data that doesn't help solve the problem at hand.

Not to sound like a broken record, but go to step #2 in the troubleshooting guide. For now, we are NOT trying to troubleshoot the entire system. We're just verifying the proper operation of a specific component, one that could be the root cause of everything. You can easily do this test on your next drive, but it's VERY important to set up the panel exactly as described. Don't bother with readings while parked. Record the values while driving:

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

Unfortunately, you ran the test with the AC on. Even if the DCCV was acting up and dumping uncommanded heat into the cabin, the cold air from the AC may be masking the true extent of the problem.

From the troubleshooting guide, with added emphasis:

"Select manual LO and medium fan speed. Press the A/C button once to turn off the compressor. The light in the A/C button should be off. Having the AC compressor off makes sure the air flowing through the ducts will not be cooled for this test. Go for a test drive and fully warm up the engine. While driving, take note of the temperature reading at the center duct on each side. Let the thermometer acclimate for several minutes in each position. If your exterior temperature display (on the control panel) seems accurate, you can use that as a reference.

If the duct temperature was warmer than exterior air, at least one valve was letting hot coolant reach the heater core and must be corrected. For best results, take these temperature readings during a test drive. This helps reduce the effect of hot air from the engine reaching the cabin air inlet at the base of the windshield."

So PLEASE do that exactly as described. We'll either know the DCCV isn't fully closing and must be corrected, or it's good and we can move on to the next step.

Keep us posted.

 

All the other epic posts say, "Please start with the introduction (Post #1 above)." Which at the beginning states to get a thermometer, and...

"Clip the pocket thermometer in the center dash vent. Before starting any troubleshooting, record the actual duct and outside air temperatures during your typical drive. It does no good to say the air feels "warm" or "cool". We need an actual value, and also need the outside air reading for comparison."

I did that, but I also wanted to take readings because I wanted to know if driver's side is getting warmer. Driver's side feels as if it's catching up to other side. Posted results.

The car's A/C was always colder when it was moving. Now it's colder at idle, warmer while driving.

I can check fuses mentioned at beginning of post #2. I planned on that anyway. On the to do list. Several other vehicles to tend to.

Right now, can't do initial driving test in post #2. Rearview mirror broke off ball stud while adjusting it. Dangling by a wire. May just have to skip to measuring temps of heater pipes.

I've read a few posts about bad DCCV's leading to Climate Control Module failure. Let's just assume this is a DCCV problem. Are 02's (build date 6/01) susceptible to such CCM failure? If so, is there anyway to prevent CCM failure? Like... preventing it by not operating A/C or heat? Or, can it happen regardless? Should I just park it?

 

If you have an infrared thermometer, that is a much more accurate method to confirm the DCCV is operating properly.


The '99-02 models don't seem to have the problem with the bad DCCV burning up the control module. If still worried about it, this outfit does a fuse protection upgrade:

- JaguarClimateControl.com

Or could also an inline fuse to the center wire at the DCCV connector. No idea of the amp rating needed, so you'd have to experiment.


But park such a beautiful car because your HVAC system is acting up? Are you nuts? The system is a bit different than most, and slightly more complex, but my tired '02 is living proof the system can work wonderfully. I love it. It's set and forget.

Now, I owe you an apology. I reread my last post and was a little brusque. That was not my intent and I am sorry. I'm just trying to help, but my alleged sense of humor doesn't always come across as intended.

 

After duct taping rearview mirror into position, I began troubleshooting, following steps in post #1 of 'epic thread'.

1. Checked Fuse 1, engine fuse box. OK.

2. Manual LO/medium fan/compressor off drive test...

Evening, dark out. Engine not run for 18 hrs. Sat in shade for several hrs prior to sunset.

Outside air temp 70°. Panel external temp 74°.

Manual LO & medium fan, A/C button/light off. Drove to fully warm engine. Temp readings each center duct obtained while driving (IR thermometer, which closely matched pocket thermo).

Left-Center duct: 90° to 92.5°
Right-Center duct: 120° to 125°

3. Parked Manual LO/HI test...

Before dawn (astronomical twilight; sun not up). Engine hadn't been run for 10 hrs.

Outside air temp 66°. Panel external temp 68°.

Started, selected Manual LO. Waited for engine to fully warm (gauge centered). Took long time... well over ½-hour. Hottest upper rad hose got was only 176.5°. This is what it's upper rad hose measures after a typical drive.

Didn't know if it was necessary to rev to 1500rpm for 2 mins, because 'epic thread' covers V6. V8 has aux coolant pump, but I understand with LO setting selected, aux pump will be off.

I revved. Took readings before & after rev. Only listing post-rev results. Pipe readings obtained (IR thermo) where cabin pipes have slight bend, just aft & below ABS pump, away from exhaust manifolds.

Manual LO results:

Upper rad hose: 176°
Left cabin pipe: 166.5°
Right cabin pipe: 166°
Return: 164.5°

Selected Manual HI. Results:

Upper rad hose: 176.5°
Left cabin pipe: 176.5°
Right cabin pipe: 182.5°
Return: 176°

Summary...

Manual LO/medium fan/compressor off drive test: Right-Center duct 30° to 32.5° warmer than Left-Center duct.

Manual LO parked test... All 3 DCCV to Core pipes were below upper rad hose temp, fairly equal.

Manual HI parked test... Right cabin pipe temp was above others by 6° to 6.5°. It was hotter than the upper rad hose.

I stopped there, for now.

 

Woo hoo, great progress. I'd say your latest test drive readings (AC off, LO selected) show the DCCV is not closing fully.

The infrared thermometer readings on the heater pipes show the same thing. I could have sworn I included the temp readings I measured, but I obviously didn't. Working from memory, all three pipes were in the low 100s after a cold start, but it's been a while. I'm out of town for a few days, but can run that test again when I get back. Your values didn't show any big increase when the DCCV was commanded open, so that confirms the diagnosis.

 

Should I go ahead & check voltage at the DCCV connector? If so, one probe of the multimeter to the center pin of DCCV? Harness side, right? Where does the other probe go?

I haven't inspected the connector, but maybe I should because of the intermittent coolant leak I had at the DCCV hose. I don't know if coolant was spraying out the hose while driving & may have gotten into the connector.

The leak only occurred twice. Once last fall, & again this spring. I only found it when I saw a spot under the car. Those 2 times I had to add coolant. I don't know why it stopped on it's own.

One thing I noticed doing the parked test, is that I smelled coolant in the engine compartment. I didn't see anything at the DCCV, or below it. I didn't look yet to find where it's coming from.

 

Nah, I wouldn't bother. When you changed from LO to HI, the pipes warmed up somewhat, so that tells us something changed. Most likely the DCCV was never fully closed, but did move towards open when commanded. That most likely means the wiring is intact.

 

When I saw the cabin pipes were less than the upper rad hose, I wondered though what their temp should be. I had thought, since a lot of the stuff around the engine was about 130°, the pipes probably should've been around 130° also, but they were 166°. That was one bit of info I couldn't confirm or find anywhere.