2001 T&C Climate Control

I believe you are on the right track, If your scanner can pull codes from the climate control/BCM you may find a fault code. The infrared detects surface temp of the drivers and passenger seat along with the back seats and adjust the temperature. If the sensor is faulty it will cause that problem.

Glenn Beasley Chrysler Tech

Glenn,

Thanks so much for your helpful reply. I actually realized that I screwed up with the quesiton I asked......

What I meant to ask is if the climate control uses input from the rear sensor even if the rear climate control is turned off?

be replaced, right? (You cant replace just the sensor...?)

Thanks again for your help!!

-gerry

BTW---I have what is mostly a generic scan tool. So, it will not pull codes from the BCM/Ac unit (Sadly....)

I would expect that I would need the chrysler scan tool to do this, correct?

Do you see those infrared sensors go bad a lot?

-gerry

Are you sure the switch for the rear isn't set to manual control by the back passengers. Sounds like it to me. Check the blower switch for the rear, Is it on?

I wish it was that simple!! :) ......You can override manual control anyway from the front. (Options are Off, Auto and Rear Control)

When you put it on Auto from the front, a lock icon appears on the rear lcd, and control is disabled.

-gerry

I guess I still don't understand what you are saying, The dual infrared sensor checks the front and rear surface temp. Yes they do go bad especially if someone were so clean the lens with a vinyl dressing.. You don't have to have a Chrysler scan tool just a scan tool that performs more options. I would start with scanning the system before just putting parts on the system.

Glenn Beasley Chrysler Tech

Okay....thanks.

This van has two sensors....One in the front that takes care of both front occupants, and one in the rear...

I was just asking if the climate control system still takes input from the rear occupant sensor even if the climate control system for the REAR is off. (And the front is on)

I ask this, because it seems as though the Rear Climate control is the erratic one, as the fan for the back goes crazy upon starting the van. Even if I shut the rear off, the front still doesnt act normally. I find it unlikely that BOTH sensors would go bad, and hence why I ask this question....

I really appreciate you help. Thats an interesting point regarding the vinyl cleaner. I do use the armor all wipes, so its possible I nuked the front sensor. But---it still wouldnt explain why the back climate control (With its own sep. sensor) goes nuts. Ive never armor all'd back there :)

Can the chrysler scan tool extract what temperature the Infrared Sensor sees? I know with my 04 Acura TL, I can put the climate control in a diag mode, and it will display a whole bunch of info about the climate control without using a scan tool. (Including the in car temp, blend door temp etc....) Similar on how you can hold the Trip button on the T&C to get OBDII codes. (Really cool feature!!) Are there any special modes to get this info out without a cabable scan tool??

Thanks again for your input. I highly value it!

-gerry

I had a similar problem with my 2001 T/C LTD and what had happened was a short in the wiring from the outside air temperature sensor which would give a faulty outside air temperature. ie. 5 degrees F would show as 76 degrees F and this input is fed to the auto climate control system which would try adjusting the cabin temp by bringing in outside air without the time delay you usually get with cold temperature starts. I ended up having to repair the wiring harness but the same situation could happen with a faulty outside air temp sensor. The control system does rely on the outside air temp to calculate the opening of the HVAC unit blend doors as well as fan speed.

Johnny

Glenn

"The infrared detects surface temp of the drivers and passenger seat along with the back seats and adjust the temperature. If the sensor is faulty it will cause that problem. "

Interesting. Do you know where the sensor(s) are in the 2001 LHS?

Thanks Bob AZ

The LH does not use the infrared sensor, it uses something called an aspirator motor. It draws cabin air over the in car temp sensor. The air flows across the resistor and of course the resistor changes resistance depending on the temp sampled. This of course adjust the temp as needed. That sensor is mounted behind the controller. If you ever suspect a problem with this, pop out the control head and blow off the little fan behind it. Those fans act as a magnet to dust.

Glenn Beasley Chrysler Tech

Johnny,

I assume with your problem, your Outside Temp gauge read faulty also, right? Ours is pretty dead on. Although once we were driving to go skiing, and I noticed that the outside temp gauge would swing +/-8 or so degrees in a very short distance on the highway. I was thinking that with Averaging, maybe I wouldnt notice a bad sensor. But maybe it was really swinging in temp driving in the mountains....

Thanks

-gerry

Its not an infrared sensor on the LH

Actually my first symptons were the outside temp display would swing up and down from 10 to 40 degrees of actual usually higher depending on how much salty roadwater got into the harness during wet winter driving. The sympton never appeared during warm weather months. But as I said before it severely affected the auto climate control when the outside temp display was reading faulty. So the ATC must really rely on the outside temperature to regulate passenger compartment temperature.

Johnny