02 Tahoe mode door issues

[smiggs]

I replaced the mode door actuator because mine defaulted on defrost. I would attempt to do the recalibration and it would just keep cycling between defrost, foot, face. Took it to the dealer and they could use the Tech 2 to get it to actuate as commanded through the computer. Suggested I purchase a new control unit. I went the rockauto route and got a new unit. Still same issue. Took it back tot he dealer and they said it had a internal fault to the new head unit. Sent it back to rockauto and the replaced it. Hooked up the new one and I still have the same problem. Got my hands on a autel maxisys reader and it shows two faults for heating and air conditioning. GM DTC B3761 & B0248. These read Airflow control 3 feedback circuit. I purchased another mode door from the dealer this time and the mode door is still not working as it should. The blower and temp select work fine. When I look at real time data it shows no min or max setting for the mode door. I'm trying to figure out where to go next. Two control panels and two mode door actuators.

 

[swathdiver]

I replaced the mode door actuator because mine defaulted on defrost. I would attempt to do the recalibration and it would just keep cycling between defrost, foot, face. Took it to the dealer and they could use the Tech 2 to get it to actuate as commanded through the computer. Suggested I purchase a new control unit. I went the rockauto route and got a new unit. Still same issue. Took it back tot he dealer and they said it had a internal fault to the new head unit. Sent it back to rockauto and the replaced it. Hooked up the new one and I still have the same problem. Got my hands on a autel maxisys reader and it shows two faults for heating and air conditioning. GM DTC B3761 & B0248. These read Airflow control 3 feedback circuit. I purchased another mode door from the dealer this time and the mode door is still not working as it should. The blower and temp select work fine. When I look at real time data it shows no min or max setting for the mode door. I'm trying to figure out where to go next. Two control panels and two mode door actuators.

Joe, could the actual door be stuck or broken? Have you been in there to check them?

 

[smiggs]

I was able to move the doors while I was installing the new actuator. They operate when the mode door is “hunting” from defrost, face, foot.

 

[johnnyCZ]

Hi there, were you able to fix the issue? I have exactly the same behavior on my '02 Avalanche. Also replaced actuator twice, and head unit once to no avail. Seems like it's some wiring issue, but initial tests for the wires continuity didn't show any issue.

I also read one TSB which tells there may be a problem in the junction connector on the right side of instrument panel (under the cover).

 

[JonnyTahoe]

Hi there, were you able to fix the issue? I have exactly the same behavior on my '02 Avalanche. Also replaced actuator twice, and head unit once to no avail. Seems like it's some wiring issue, but initial tests for the wires continuity didn't show any issue.

I also read one TSB which tells there may be a problem in the junction connector on the right side of instrument panel (under the cover).

Having that issue with my 00 Yukon. Bought Brand new AC Delco Mode Actuator P/N; 52473356 moved about a half turn then stopped. Swapped my spare actuator from my Tahoe into the Yukon no movement at all swapped it back into the tahoe now it won't work at all. New Delco actuator wont work in the Tahoe either. Seems the Yukon is burning out these Actuators. No clue what to do worked fine for 20 years now this. Thanks for your info I have had it with this for now.

 

[George B]

Having that issue with my 00 Yukon. Bought Brand new AC Delco Mode Actuator P/N; 52473356 moved about a half turn then stopped. Swapped my spare actuator from my Tahoe into the Yukon no movement at all swapped it back into the tahoe now it won't work at all. New Delco actuator wont work in the Tahoe either. Seems the Yukon is burning out these Actuators. No clue what to do worked fine for 20 years now this. Thanks for your info I have had it with this for now.

Do you have a scanner like a tech2 to view it with?

 

[JonnyTahoe]

Do you have a scanner like a tech2 to view it with?

No scanner never needed one. First time I ever had anything like this happen other than a few Blower Modules.

 

[JonnyTahoe]

Joe, could the actual door be stuck or broken? Have you been in there to check them?

I'm having the exact same problem.

 

[Fless]

No scanner never needed one. First time I ever had anything like this happen other than a few Blower Modules.

You could use one now.

 

[George B]

You could use one now.

This^^^
I threw parts at our Envoy until I had a Tech2. It's fixed now.