Tahoe has no rear heat - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**Boog** · 11-04-2012, 05:44 PM

My '03 Tahoe with rear climate control is only blowing cold air.
I removed the temp door actuator and it was turned full to the cold side. I unplugged it, removed the cover and manually reset it to center then plugged it back up and it immediately turned to full cold again. For now I centered the actuator and left it unplugged so it does blow warm air.
I found a thread on another site on this topic. Some say the module is bad, some say it was the actuator. How do I test the actuator to know that it is really bad? Or the module? I understand either of these will set a dtc but it's only detectable with something more than just the low end scan tool. I have an Innova tool.
This is only and air distribution issue as there is plenty of hot water going to the heater core.

clinebarger · 11-04-2012, 07:54 PM

GM has an updated control module that "usually" takes care of that. They programed out all the Over-travel logic DTC's in the module.

**Boog** · 11-04-2012, 09:37 PM

So since the actuator does move it is ok? We know it is a faulty module now?

wuss721 · 11-05-2012, 12:11 AM

I had that problem with my 2001 chevy tahoe the front would blow hot air and the rear cold. I disconnected the water lines to the heater core and put a water hose to clean it out. That worked for me. Might want to try it out.
Posted via Mobile Device

clinebarger · 11-05-2012, 09:25 PM

Quote:

Originally Posted by Boog

So since the actuator does move it is ok? We know it is a faulty module now?

Hard to say 100% without codes,
Get the P/N off the module.....I will try to decode it, May have the update module already?

**Boog** · 11-06-2012, 08:32 PM

Well I have it set to blow warm air and put it back together so she can run it. Would the parts stores have the updated modules? I really don't want to have to buy one from our local dealer.

clinebarger · 11-06-2012, 10:16 PM

Quote:

Originally Posted by Boog

Well I have it set to blow warm air and put it back together so she can run it. Would the parts stores have the updated modules? I really don't want to have to buy one from our local dealer.

It's Possible if the part store is a "high volume" AC Delco dealer.

**Boog** · 10-07-2013, 07:53 PM

Quote:

Originally Posted by clinebarger

Hard to say 100% without codes,
Get the P/N off the module.....I will try to decode it, May have the update module already?

Alright CB. It's getting to that time of year when we'll need the rear heat working.

The rear actuator numbers are:
16164972 green S
bar code N3331533C
33518509

control module:
Red Gray
serial 0540
bar code 15185966

What do you think?

clinebarger · 10-24-2013, 09:16 PM

The updated module # is 15832319.

15185966 is the original out dated module.

**Boog** · 10-24-2013, 10:46 PM

I suspected mine was original. Since the actuator moves in both directions it can be considered ok and I should replace the module then.
Ok CB. Thank you.

**Boog** · 11-27-2013, 11:36 PM

I finally put on that new module tonight. The temp door moved to the warm side so I guess it's fixed. It's cold out so I didn't mess around long out there.
Thanks CB for the help and part number.

clinebarger · 11-28-2013, 09:14 PM

Quote:

Originally Posted by Boog

I finally put on that new module tonight. The temp door moved to the warm side so I guess it's fixed. It's cold out so I didn't mess around long out there.
Thanks CB for the help and part number.

Your welcome.

1tonchevy · 12-10-2013, 07:31 PM

Where is the actuator flap on these? My truck does the same. Thanks

**Boog** · 12-10-2013, 11:31 PM

On the Tahoe and Suburban the rear heat/ac unit is behind the side panel on the right rear of the vehicle. Snap the trim loose and a couple of screws and pull the panel off. One door actuator is at the front and one at the rear and the control module is mounted in the center.

68 TT · 04-15-2014, 12:26 AM

Quote:

Originally Posted by 1tonchevy

Where is the actuator flap on these? My truck does the same. Thanks

Here you go. It is behind the actuator just to the left of the blower motor. The control module is the box with the two blue connectors about a foot to the left of that.

68 TT · 04-15-2014, 12:30 AM

I just posted more info in another thread.

http://67-72chevytrucks.com/vboard/s...3&postcount=14

Hope this can help somebody else out.

No rear heat in the winter sucks for the kids. My temp fix cost nothing and can be done in a few minutes if the parts to fix it right are not on hand when you need rear heat.

11-04-2012, 05:44 PM	#1
Boog laying low Join Date: Mar 2001 Location: Searcy, Ark. USA Posts: 12,955	Tahoe has no rear heat My '03 Tahoe with rear climate control is only blowing cold air. I removed the temp door actuator and it was turned full to the cold side. I unplugged it, removed the cover and manually reset it to center then plugged it back up and it immediately turned to full cold again. For now I centered the actuator and left it unplugged so it does blow warm air. I found a thread on another site on this topic. Some say the module is bad, some say it was the actuator. How do I test the actuator to know that it is really bad? Or the module? I understand either of these will set a dtc but it's only detectable with something more than just the low end scan tool. I have an Innova tool. This is only and air distribution issue as there is plenty of hot water going to the heater core. __________________ Boog 69 Chevy stepside, 358/T350, 4.11 posi, 4.5/4 drop, rallys, poboy driver primer is finer 91 Chevy sportside, Tahoe, Yukon & GMC Crewcab All GM..'nuff said. I stand for the flag and kneel at the cross

11-04-2012, 07:54 PM	#2
clinebarger Senior Member Join Date: May 2009 Location: Fort Worth, TX Posts: 6,370	Re: Tahoe has no rear heat GM has an updated control module that "usually" takes care of that. They programed out all the Over-travel logic DTC's in the module.

11-04-2012, 09:37 PM	#3
Boog laying low Join Date: Mar 2001 Location: Searcy, Ark. USA Posts: 12,955	Re: Tahoe has no rear heat So since the actuator does move it is ok? We know it is a faulty module now? __________________ Boog 69 Chevy stepside, 358/T350, 4.11 posi, 4.5/4 drop, rallys, poboy driver primer is finer 91 Chevy sportside, Tahoe, Yukon & GMC Crewcab All GM..'nuff said. I stand for the flag and kneel at the cross

11-05-2012, 12:11 AM	#4
wuss721 Registered User Join Date: Dec 2011 Location: McFarland, CA Posts: 55	Re: Tahoe has no rear heat I had that problem with my 2001 chevy tahoe the front would blow hot air and the rear cold. I disconnected the water lines to the heater core and put a water hose to clean it out. That worked for me. Might want to try it out. Posted via Mobile Device

11-06-2012, 08:32 PM	#6
Boog laying low Join Date: Mar 2001 Location: Searcy, Ark. USA Posts: 12,955	Re: Tahoe has no rear heat Well I have it set to blow warm air and put it back together so she can run it. Would the parts stores have the updated modules? I really don't want to have to buy one from our local dealer. __________________ Boog 69 Chevy stepside, 358/T350, 4.11 posi, 4.5/4 drop, rallys, poboy driver primer is finer 91 Chevy sportside, Tahoe, Yukon & GMC Crewcab All GM..'nuff said. I stand for the flag and kneel at the cross

10-24-2013, 09:16 PM	#9
clinebarger Senior Member Join Date: May 2009 Location: Fort Worth, TX Posts: 6,370	Re: Tahoe has no rear heat The updated module # is 15832319. 15185966 is the original out dated module.

10-24-2013, 10:46 PM	#10
Boog laying low Join Date: Mar 2001 Location: Searcy, Ark. USA Posts: 12,955	Re: Tahoe has no rear heat I suspected mine was original. Since the actuator moves in both directions it can be considered ok and I should replace the module then. Ok CB. Thank you. __________________ Boog 69 Chevy stepside, 358/T350, 4.11 posi, 4.5/4 drop, rallys, poboy driver primer is finer 91 Chevy sportside, Tahoe, Yukon & GMC Crewcab All GM..'nuff said. I stand for the flag and kneel at the cross

11-27-2013, 11:36 PM	#11
Boog laying low Join Date: Mar 2001 Location: Searcy, Ark. USA Posts: 12,955	Re: Tahoe has no rear heat I finally put on that new module tonight. The temp door moved to the warm side so I guess it's fixed. It's cold out so I didn't mess around long out there. Thanks CB for the help and part number. __________________ Boog 69 Chevy stepside, 358/T350, 4.11 posi, 4.5/4 drop, rallys, poboy driver primer is finer 91 Chevy sportside, Tahoe, Yukon & GMC Crewcab All GM..'nuff said. I stand for the flag and kneel at the cross

12-10-2013, 07:31 PM	#13
1tonchevy C35 Crew Dually Join Date: Nov 2008 Location: Belleville Ontario Posts: 1,116	Re: Tahoe has no rear heat Where is the actuator flap on these? My truck does the same. Thanks __________________ If it aint square, I don't care. 84 C35 CC Dually Project log... http://67-72chevytrucks.com/vboard/s...d.php?t=414892

12-10-2013, 11:31 PM	#14
Boog laying low Join Date: Mar 2001 Location: Searcy, Ark. USA Posts: 12,955	Re: Tahoe has no rear heat On the Tahoe and Suburban the rear heat/ac unit is behind the side panel on the right rear of the vehicle. Snap the trim loose and a couple of screws and pull the panel off. One door actuator is at the front and one at the rear and the control module is mounted in the center. __________________ Boog 69 Chevy stepside, 358/T350, 4.11 posi, 4.5/4 drop, rallys, poboy driver primer is finer 91 Chevy sportside, Tahoe, Yukon & GMC Crewcab All GM..'nuff said. I stand for the flag and kneel at the cross

04-15-2014, 12:30 AM	#16
68 TT Still plays with trucks Join Date: Jul 2009 Location: Spokane, WA Posts: 3,556	Re: Tahoe has no rear heat I just posted more info in another thread. http://67-72chevytrucks.com/vboard/s...3&postcount=14 Hope this can help somebody else out. No rear heat in the winter sucks for the kids. My temp fix cost nothing and can be done in a few minutes if the parts to fix it right are not on hand when you need rear heat. __________________ miSSed opportunity - ground up creation of an AWD 1994 454 SS that never was http://67-72chevytrucks.com/vboard/s...d.php?t=795577 69 C10 shortbed stepside 400 small block - built like what a super sport truck could have been 69 K20 lwb TBI 350 4L60E NP208 14-bolt Dana-44 w/disc 68 Camaro SS / RS 500hp 439 inch roller cam big block 4L80E 79 Malibu TPI 350 4L60 w/ Z28 steering & sway bars



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