I have a 07 Avalanche LTZ that will not unlock the back doors and tail gate when the unlock sensor on the driver or passenger door are pressed or if the unlock button is press on the keyless remote.

open and check linkage

Depending on what you have for diagnostic knowledge and tools. You may want to send it in for diagnostics and repair. I can tell you that your vehicle's BCM (Body Control Module) controls these circuits. If it was a t my shop. I would first look for any fault codes. Then through the scan tool, manually command the doors to lock and unlock. Depending on what I find, take a closer look at the master control switch. This is in the drivers door and opens/closes windows and locks/unlocks doors. I'm forwarding you a couple wiring schematics just in case. I don't want to slow you down. FYI under the hood, inside the power distribution box. There is a relay for the tailgate lock/unlock. Any questions please feel free to write back. Good Luck.

YouTube reset for fob had same problem.

Dannie, power lock actuator faulty. Check the attached links,instruction and guides, Good luck
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Try pressing the unlock button twice

I have an 07 avalanche that did that to to the rear window. It was the switch. Take drivers side switch plate off and use one of the good switches on the drivers door. If it works roll it all the way to top and get urself a new switch. iIf it does not work then its the window motor. Good luck.............

TRY THIS PRESS REMOTE TRANSMITTER LOCK BUTTON ACTIVATES ALARMS AND LOCKS ALL DOORS.NOW PRESS REMOTE TRANSMITTER UNLOCK BUTTON DEACTIVATES ALARM AND UNLOCKS ALL DOORS AND TRUNK LID.IF VECHICLE UNLOCKED AND DOORS OR TAIL GATE NOT OPEN WITH IN 30 SECONDS LOCKS AND ALARM ARE REACTIVATED.IF YOU STILL HAVE TROUBLE WITH DOOR LOCKS THE DEALERSHIP HAS TO FIX.

sounds like the main acculator in the drivers door has gone bad have it replaced it should solve your problem.

Probably a loose connection or fuse (start with the fuse and then look for a loose connection in the door)

Actually I found a solution. I remove the lock relay form the fuse panel and placed it back in place. I did not replace it. After doing this they worked. I probably need to replace the relay at some point, but for now that solved the problem. It was hard for me to believe that there is a separate relay for the lock and unlock circuit.