jlenkows

Has anyone noticed or experienced an 'issue' with their 07 'Hoe whereas the A/C doesn't blow ice cold unless you drop the thermostat to 61 (or so) degrees??? I've been struggling with this issue and just made the appointment with the dealership but want to have supporting docs if possible when I go in there.

The service dude already positioned himself by telling me that they had a few 'Hoes in with similar problems and GM gave the standard line of "it's functioning as designed".

73shark

I finally decided to operate it manually on short, in-town trips and use auto for long trips. The auto mode in town seems to blow hard and cold initially then cuts way back unless you dial the temp way down.

jojokealoha

i've noticed mine is gradually losing its coldness as well. but then again so cal is heating up and it might just be relative. guess i'll take mine in for testing too.

engine2

Do let him sell you that its normal. I live in the hot, humid climate and as long I set it at 71 or below it blows ice cold hard until it reaches the desired temp. If I set temp higher it still blows cold but just not as hard. In fact I am very impressed how quickly it cools the entire SUV.

tahoe07

I don't think he ever said it was on auto.

Yes on auto mine also blows less hard but seems to keep about the same temp of air morre or less.

jlenkows

I'm not a great fan of Auto - I prefer to have constant airflow - not only when it's trying to achieve it's set temp.

My problem is on manual....

ZX1100F1

In the manual mode the digital temperature readout means very little.
When in the manual mode think of the temp display the same as you would a round dial, all the way counterclockwise (or 60 degrees with the digital display) is the coldest setting and likely were you would set the temp on a hot day if you had the base system.
When at 60 degrees in manual mode you should notice the temperature of the airflow increase at each single degree you go up, this is normal operation.
Now if you are at 60 and the temp is not ice cold then you have a problem otherwise you are good to go.

jlenkows

OK... well beyond my surprise, the dealer actually was able to reproduce the problem and DIDN'T give me the annoying company line... They actually found a TSB to correct the problem - #06-01-39-008 which is supposed to update the HVAC controls.

The temps here in NY have been in the high 60's/low 70's so I can't quite test to see if they really did fix anything, but... the fact that they didn't blow me off (no pun intended) is rather impressive.

Now for the ZX question - what exactly is this bulletin????

ZX1100F1

Here is the TSB However keep in mind that this will only effect the operation of the HVAC while you are in the AUTO mode and since you aren't a big fan of the Auto mode you are likely not going to experiance any difference.






Document ID# 1860902
2007 Chevrolet Tahoe - 4WD
[hr] [align=left] Subject: Automatic HVAC System Set Temperature Does Not Provide Comfort (Update HVAC Control Module Software) #06-01-39-008 - (09/07/2006)[/align] [align=left] Models: 2007 Cadillac Escalade Models[/align] [align=left]
2007 Chevrolet Avalanche, Suburban, Tahoe[/align] [align=left]
2007 GMC Yukon Models[/align] [align=left]
with Automatic Temperature Control HVAC System (RPO CJ2)[/align]
[hr] Condition Some customers may comment that they have to adjust the Heating, Ventilation and Air Conditioning (HVAC) system set temperature lower to get the system to blow cool air. For example: If the customer wants to keep the in vehicle temperature at 22°C (72°F), they may have to reset the HVAC control head temperature setting to 18°C (65°F) or lower to achieve the desired 22°C (72°F). Cause This condition may be caused by an HVAC control module software anomaly. Correction Do This Don't Do This Update the HVAC control module software. Do not replace any HVAC system components. Technicians are to reprogram the HVAC control module with new service calibrations contained in TIS version 5.0 or later, which has already been released. Refer to the HVAC Control Module Programming and Setup procedure in SI for more information. As always, make sure your Tech 2® is updated with the latest software version. Warranty Information For vehicles repaired under warranty, use: Labor Operation Description Labor Time D4707 HVAC Control Head Module or Assembly Reprogramming with SPS Use Published Labor Operation Time Add Diagnosis Time GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.


[hr]
Document ID# 1860902
2007 Chevrolet Tahoe - 4WD

fredster

Wow. I thought I was going nuts. The auto setting on mine does exactly the same thing. Into the dealer it goes!