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2004 chevy trailblazer_ls_ext
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Maybe this will help....Technical Service Bulletin #04-01-38-019A addresses all 02 - 05 T/B, Envoys, Rainers, etc. for poor A/C cooling efficiency following engine start-up, low speed driving and idling condition in high ambient temperature situations. This bulletin applies to all of the above vehicle built before June 2005. Certain vehicle built in June, 2005 already have had this update and those vehicles would have to be checked to see if the update has been performed. The update involves replacement of the electric cooling fan and a PCM recalibration.
The condition involves no-to-insufficient fan operation during these conditions. The A/C condenser and A/C compressor head temperatures rise and cause cool-down efficiency to suffer. While driving, air flow across the condenser is sufficient and A/C performance is good. The update commands additional fan speed operation at low engine RPMs and idle condition. Air flow across the condenser helps in heat transfer and lowers A/C pressures, hence cooler air. I have an '04 and we have been experiencing some warmer days of 80-85 degrees, sunny, but lower humidity numbers. Currently, my A/C system works great...I did do the PCM calibration as it was available at an earlier date (TSB 04-06-02-005). I am considering installation of the update clutch fan assembly. I currently have not performed this update on any vehicle, so I can't give first-hand comment on the result(s).
 

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2005 chevy trailblazer_lt
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Is this a problem that i can take into my dealer and get fixed under warranty mine is a 05 and when its hot out until i get going man it sucks way to hot

shay
 

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2003 chevy trailblazer_ls
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04TBEXT said:
Maybe this will help....Technical Service Bulletin #04-01-38-019A addresses all 02 - 05 T/B, Envoys, Rainers, etc. for poor A/C cooling efficiency following engine start-up, low speed driving and idling condition in high ambient temperature situations. This bulletin applies to all of the above vehicle built before June 2005. Certain vehicle built in June, 2005 already have had this update and those vehicles would have to be checked to see if the update has been performed. The update involves replacement of the electric cooling fan and a PCM recalibration.
The condition involves no-to-insufficient fan operation during these conditions. The A/C condenser and A/C compressor head temperatures rise and cause cool-down efficiency to suffer. While driving, air flow across the condenser is sufficient and A/C performance is good. The update commands additional fan speed operation at low engine RPMs and idle condition. Air flow across the condenser helps in heat transfer and lowers A/C pressures, hence cooler air. I have an '04 and we have been experiencing some warmer days of 80-85 degrees, sunny, but lower humidity numbers. Currently, my A/C system works great...I did do the PCM calibration as it was available at an earlier date (TSB 04-06-02-005). I am considering installation of the update clutch fan assembly. I currently have not performed this update on any vehicle, so I can't give first-hand comment on the result(s).
With this info i would take it and have them check to make sure.
 

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The content of this bulletin I previously posted, could apply after basic A/C system diagnosis reveal no deficiences in the A/C system. If you are discussing this condition with your dealership, you may advise them of your concern (insufficient A/C temperature output), advised them you're aware of the bulletin, but don't know if there may be some basic A/C problem with the vehicle. Actual A/C temperature output varies based on outside temperatures and relative humidity, so you can't rightfully say an A/C system is deficient because it will not blow below, say 65 degrees F. On a 90+ degree day with humidity above 90%, A/C system temperature output may be 75 degree at best. Parking in the sun, glass area, non-use of the recirculation mode can hamper A/C performance. Also to all you Auto A/C system people...with the blower motor in "AUTO" mode, the A/C control head limits blower speed to 80% maximum. If you want full (100%) blower motor speed, you need to crank the blower motor over manually to "FULL".
 

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I went to the dealer today with the TSB referenced above and was told that it only refers to EXT editions and the efficiency of rear A/C cooling.

Bummer.
 

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2004 chevy trailblazer_ls_ext
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I gotta a bridge you might wanna' buy...

:confused: Hey Guys... Whoever told you the bulletin I previously posted was for EXT chassis only was involved with too much "sucky-sucky" on the "happy pipe". Ask your dealership if they could pull up that bulletin number on their TIS 2000 so you may read it. If they can't find it by Technical Service Bulletin number, the Document number is...like...1671108...man... If after the smoke clears, they can't find it, post a fax # to my private message section and I'll fax you the complete bulletin.
 

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2005 gmc trailblazer_lt
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I'll be honest, I'm an A.C. whore. I HATE heat so I use the air conditioning more than anyone I've ever met.

From my experience, all cars I have ever owned or driven seem to cool the car better while driving than while stopped. Sometimes it's very noticable, sometimes it's not- but it's always there.

I've always assumed it does that because the engine isn't turning the compressor fast enough, similiar to the way that the headlights in some cars will get brighter when you step on the gas because at idle the alternator isn't turning fast enough to be at it's maximum efficiency.
 

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I agree AC's cool better when being driven. But my TB blows some serious hot air with the AC on until you start driving the thing. Increasing the RPM's in Park to 1000 or 1500 doesn't help a bit. The car we traded in (a 01 Grand Am 4cyl) and my current truck (02 z71) blow cold air in Park, and it only gets colder upon driving it.

04TBEXT: You've got a message... :)
 

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2003 chevy trailblazer_ls_ext
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I need to schedule an appointment, mine does the exact same thing. If you don't drive down the road a good ways it will cook you. It could idle for an hour with the recirculation on and ac on and never get cool at all.
 

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2002 gmc
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I found something on the A/C Problem. Not working very well when at idle. GM KNows About it..

Bulletins - October, 2002

01 – HVAC

02-01-39-005; HVAC System Inoperative for a Drive Cycle, Poor HVAC System Performance in High Ambient Temperatures (Update HVAC Control Module Software); 2002-03 Chevrolet TrailBlazer, EXT, GMC Envoy, XL, Oldsmobile Bravada

Dunno If this will help or not..

Russ
 

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2005 isuzu ascender
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This is good info. I had to pick my mother up from the beauty shop. Got there about 10 minutes early, so sat in the Ascender with the AC on high. Just warm air was coming out. I'll take it in next week and see what they say.
Thanks,
jeff
 

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thebeast said:
This is good info. I had to pick my mother up from the beauty shop. Got there about 10 minutes early, so sat in the Ascender with the AC on high. Just warm air was coming out. I'll take it in next week and see what they say.
Thanks,
jeff
Was your recirc on? I swear I've never had a problem with my AC blowing warm under ANY circumstances.
 

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2007 chevy trailblazer_ss_1ss
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Discussion Starter #36
02EnvoySLE Guy said:
Was your recirc on? I swear I've never had a problem with my AC blowing warm under ANY circumstances.
My recirc is always on when I have this problem, but it also does it when it is off. It only happens to me when its really hot outside. Early in the morning and late in the evening, snow flakes come out of those vents!! :eek:
 

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yea mine is only bad when its in the middle of the day, otherwise its cold as heck,

shay
 

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OK, it hit 98 here yesterday and I see what the complaint is about. Even under recirt and after 15 minutes of driving, when I would slow down, or sit still at a light the air would get warm. Felt like I was on vent. :( Now I can see why people are upset. Before now it has only got up to around 87 or so.
 

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2007 chevy trailblazer_ss_1ss
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Discussion Starter #39
MoJoe said:
OK, it hit 98 here yesterday and I see what the complaint is about. Even under recirt and after 15 minutes of driving, when I would slow down, or sit still at a light the air would get warm. Felt like I was on vent. :( Now I can see why people are upset. Before now it has only got up to around 87 or so.
Jump on board with us pissed off sweaty hot people, MoJoe!! :laugh:
 
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