Hi,

I bought an X-Reg (2000) S-Type 3L SE a couple of weeks ago. When I bought it, the climate control would constantly pump out hot air. But over the past few days, it's mostly been producing only freezing cold air. Occasionally it will produce warm air but I can't figure out any pattern to this. It is independent of the temperature setting - HI, LO or in between seems to make no difference.

The engine temperature gauge is sitting rock steady in the right place and coolant level seems to be okay (ie there is coolant in the top tank).

Is there a common cause of this problem that I should be investigating? A Google search turns up lots of people who have constant hot air (control valve failure) or hot air at HI and cold air at LO but nothing in between (sensor failure) but nothing that quite matches my symptoms.

Thanks,
Tom

 

Tom,

Your climate control display unit might have burnt out. Lots of info here.

 

Could be a sticking DCCV.
There's an Ext temp sensor, ignore the ECT (as does the a/c).
www.jaguarclimatecontrol.com

 

Some more details on this.

On my commute in this morning (longer than usual because I remembered half way that I'd forgotten my laptop ) the climate control appeared to be speed dependent. Below ~40mph it stays cold; just above 40mph it starts to warm up. After doing about 4 miles at 60-70mph it got hot and stayed that way for the next 20-30 minutes of crawling in traffic, but eventually cooled down again.

My guess is that this is related to engine temperature/cooling system pressure and therefore is likely to be a sticking DCCV - does that sound plausible?

Cheers,
Tom

 

And, credit where it is due, when I say 'remembered half way that I'd forgotten my laptop' what I mean is 'my wife called when I was half way to point out that I'd forgotten my laptop.'

 

Check out the link below and see if it helps you to troubleshoot the problem it sounds to me that the DCCV is not doing what it should be doing. Does the temperature change on the passenger side from the driver’s side? Have you checked the coolant level?

Link JagRepair.com - Jaguar Repair Information Resource

 

Yes, the coolant level is fine. The DCCV is looking suspect, though AFAICT the temperature is the same both driver's and passenger's side, so any failure is the same in both sides - weird.

 

Pull the plug from the DCCV and check voltage. When you pull the plug (and it will not be easy) you will see three contacts the one in the middle is common and the ones on either side control the valve so turn the heat temp up for both sides and see if you have voltage. When you do this be sure not to short out the test points a little tape on the meter probes will lessen the possibility. If you have voltage for both then I would say the DCCV is likely the problem.