2001 Grand Caravan Climate Control diagnosis and code reset

Allen, What is the problem you are having?

Glenn Beasley Chrysler Tech

Just in case you're not on the dodge group:

Well, it's a long and kinda painful story, but here goes since you asked! My Caravan was struck by lightening and it knocked out the radio (just the AM band, oddly), the back up lights, the ability to control the temperature, the two zone (driver/passenger) feature and the blend doors (defrost, vent, floor)

I was able to diagnose the back up lights. The BCM was the culprit there and I replaced it only to find that my OBD tool wouldn't read codes or clear them like it used to and it added a code about a major and minor exhaust leak as well as O2 sensor faults as soon as I installed the new BCM. I then decided to ask a friend to replace the tiny chip that was at fault for the backup lights in the old unit with the same one from the "new" BCM(the damage to it was quite apparent) and he did so successfully. The backup lights then worked but I retained the new fault codes and was still not able to navigate the OBD system as I used to.

I have taken apart the motors that control the blend doors and they respond well to a 9 volt battery--they all operate both directions depending on the polarity provided. The doors themselves can be manipulated by hand.

When I do the calibration test now (at 25ish degrees) the recirc button merely flashes after the other lights go out. Don't know if that is because it is too cold to do the test or if the flashes are a code (although they are very regular and go on forever...)

There, how's that for too much information?

Thanks,

Allen

Ok your talking about Checking codes in the BCM and your code reader said it added a code for the o2 sensor to the BCM? No such code in the BCM! If your using a code reader it may not read BCM faults. Are your reading BCM faults? If so what are the faults now. What and why qould you add a chip to a BCM that you just replaced? Why didnt the new BCM come with this so called "Chip"?

Have you tried to access faults codes from the climate control Module with your scan tool? If so what are the faults? And you still havent said what the problem is that you are having with the climate control.

NOT ENOUGH INFO!!!

Thanks for responding. Okay, I'll try to be a bit more clear than i was:

My code reader is an OBDII and does not give access to non powertrain codes. I didn't mean to imply that it did. It's just that before I replaced the BCM I didn't have any codes and after I replaced it I immediately got the O2 codes. Since it happened immediately after I installed the new BCM I thought that it was perhaps related to the new BCM. That's why I took the chip out of the new BCM, installed it on the old BCM and reinstalled the old BCM (with the good chip from the new BCM)on my car. The backup light problem was then fixed but I still had the problem of the inability to control the temperature, the two zone (driver/passenger) feature and the blend doors (defrost, vent, floor)

Part of the problem I am having is that I can not get the codes and was wondering if there was a way of pressing various buttons on the climate control (it is a manual control, by the way, no digital readout) to generate error codes.

The O2 codes may be a coincidence but I really need to figure out the HVAC situation.

Thanks.

The o2 sensor fault was probably set because the 02 sensor has a problem and is getting ready to crap out all together. When an 02 goes out, normally the lite will go on and off. Get yourself a scan tool that is capable of reading body codes!!! This will give you all communication faults between the modules, including climate control, air bag, Abs and so on

It probably was a coincidence, you still need a scan tool to see what is going on between the climate control module and BCM

Thanks for the advice, I'll start shopping for an updated tool.

Allen