Dual Climate Control Question

I have a 2000 Grand Prix GT with 131,000 miles. Here's the issue, on hot summer days the drivers side air is much less cool than the passenger side air. Today I took some readings and here's what I found:

Out side air temp. - 81F

Passenger side Air

Set @ 60F
Reads 47F

Set @ 80F
Reads 80F

Drivers Side Air

Set @ 60F
Reads 60F
Set @ 80F
Reads 92F

Any thoughts or ideas? I'm hoping it's something easy to fix but knowing the luck of garage mechanic it's never easy. Also, I was looking under the hood at the freon ports and noticed a different nipple that what I'm used to. Usually the ones I've seen have outside threads but these have inner threads. When I went to Autozone they didn't have a clue what I was talking about. Even if I were to buy a can of 134a I don't see how I get the freon in the line.

Thanks,

Jeff

it sounds sort of like a controll head malfunction. Do a search of the forums, there is a way to get a trouble code and diagnose it by pushing a certain sequence of buttons.

The refrigerant connections you are used to with threads on the outside are from r12 systems. The ones on your car with inside threads are r134a systems.

Go Here

http://www.automotiveforums.com/vbulletin/showthread.php?t=616481

I'll try the diagnstic, but to be honest it's a bit confusing on how to interpret if there is an issue or not. I am thinking it migh be a temp sensor (if it exists).

Thanks fo the reply by the way.

Jeff

yeah, give it a shot. If you get some codes, Post them here. We'll try and help out with interpretation. I had a problem with mine where outside temp only said 50 degrees. It could by 90 or -10. It said 50. I replaced the outside temp sensor and it didnt fix the problem. So one day I had to remove my battery for an unrelated matter an found a connector not pluge together. Thinking it was odd, I hooked them up. When I started my car, outside temp worked. Been working ever since.

BTW, Welcome to AF. Hope we can help out as best we can.

I ran the diagnostic and this is what I got:

-00 105/106
-01 93
-02 117
-03 140
-04 00
-05 78
-06 146
-07 152
-08 155
-09 155
-10 04
-11 02
-12 74/75
-13 00
-14 00
-15 14
-16 122
-17 183
-18 55
-19 177
-20 120
-21 00
-22 116

Could some please inform me what all this "jiberesh" means?

Thanks,

Jeff

Anyone have any ideas or input?

No my wifes dual climate control system is completely dead. It will not blow anything out the vents and will not respond to any push of any of the buttons.

You guys have any input?

Thanks,

Jeff

most of the numbers here are irrelevant to a DIY. They indicate current desired positons of all the various actuators and sensors. The only thing you need to look at right now are the trouble codes, which are after the -00.

2 digit codes are current faults, 3 digit codes are history faults

105= left (drivers side) mix(temp) door open or shorted
106= right (pass side) mix(temp) door open or shorted

It appears that both of your temp door actuators have had issues in the past, and the drivers side didn't happen to be in a wrong position or the car wasn't warmed up completely to get current values when you ran the diagnostic or there would probably be a current code also (05).

To understand or diagnose the other numbers, you'd need a scan tool capable of reading body and data link codes (like a GM Tech-II).

I will rerun the diagnostic tonight then and see if i get different numbers. Thanks for the input.

Jeff

Looking at the charts, I didn't see a value in the diagnostic to compare current vs desired actuator value to see if it is off. It did list values for max cold, max hot and desired, but no current value. It showed a feedback value (which your's was at 00) but I'm not that familiar with it to say that is the current position. Anyone else on here know?

IMO the OP is just spinning his wheels. Instead of messing with the CJ2 diagnostics and not fixing the issue which is poor cooling on the driver's side versus passenger get back to HVAC basics. This issue is normally caused by a low or improper refrigerant charge versus the temperature actuators. There are discrepancies in what the R134 charge should be in various Grand Prix models from '97 and up. Many ID labels and service manual/owner's manuals were incorrect. GM has now established that the refrigerant charge should be 36 ounces on all models.

If you do not have the proper HVAC diagnostics equipment like decent R134 style manifold gauges to check low and high side pressure and do the recharge then best to take it to a pro.