Why won't rear passenger door unlock with auto lock switch?

Door Lock System Components
The power door lock system consists of the following components:
• Driver door module (DDM)
• Passenger door module (PDM)
• Door lock relay--Located in the instrument panel (I/P) fuse block and controls the locking of the rear doors.
• Door unlock relay--Located in the I/P fuse block and controls the unlocking of the rear doors
• Body control module (BCM)
• IP BEC
• Reversible door lock actuators in each door

Driver and Passenger Lock System Operation
The front power door lock switches are integral components of the driver door module (DDM) and passenger door module (PDM). The switches are two-position normally open rocker switches. When placed in either the lock or unlock positions, the switches provide a direct input to the DDM or PDM. The DDM or PDM monitor these inputs and send a LAN message indicating a change in the switch position. Modules, that activate the power door lock motors, receive the LAN message and activate the motor in the appropriate direction to lock or unlock the vehicle doors. The body control module (BCM) upon receipt of a lock or unlock signal will control the rear door lock or unlock relays and also send a LAN message to the DDM and PDM to perform the commanded function.
The modules that activate the power door lock motors are:
• DDM (driver door lock actuator)
• PDM (passenger front door lock actuator)
• BCM (both rear door lock actuators)
The DDM and PDM are directly connected to the respective door lock actuator through the door lock motor lock and unlock circuits. Once a door lock or unlock request has been received, the module will supply battery voltage to one side of the actuator and ground the other, causing the doors to lock or unlock.
The rear passenger doors are controlled by the BCM through the rear door lock/unlock relay which is incorporated onto the printed circuit board in the LH BEC. The BCM controls the unlock relay by providing ground to energize the coil and controls the lock relay by providing battery voltage to energize the relay coil. This energizes the relay and allows voltage to be applied to either the door lock motor lock or unlock circuits. Since the other side of the door lock actuator is connected to the normally closed contacts of the opposing relay to ground, the doors lock or unlock.

None < LGM - liftgate control module inside the lift gate does .
Rear Wiper/Washer System Components
The rear wiper/washer system consists of the following components:
• Rear window wiper motor
• Rear washer pump
• Rear wash relay
• Rear wiper/washer switch
• RR WIPER Circuit Breaker 15A / ENDGLASS REG Circuit Breaker 30A
• WASH 20A fuse
• Body control module (BCM)
• Liftgate control module (LGM) / End gate module (EGM)

Your best bet , take it to a qualified repair shop. You have no idea of the complexity of these system's . Communication network between modules etc..... Could have DTC'S diagnostic trouble code's stored in the liftgate control module . An auto parts stores can not read these codes .

Power Door Lock Operation
The power door lock switches are integral components of the DDM and PDM. The switches are two position normally open rocker switches. When placed in either the lock or unlock positions, the switches provide a direct input to the DDM or PDM. The DDM or PDM monitors these inputs and sends a Class 2 message indicating a change in the switch's respective position. Modules which activate the power door lock motors receive the Class 2 message and activate the motor in the appropriate direction to lock or unlock the vehicle's doors and liftgate. The modules which activate the power lock motors are:
• DDM (driver door lock actuator).
• PDM (passenger front door lock actuator).
• BCM (both rear door lock actuators).
• LGM (liftgate door lock actuator).
The DDM, PDM and LGM are directly connected to the respective door lock actuator through the door lock motor lock and unlock circuits. Once a door lock or unlock request has been received, the module will supply battery voltage to one side of the actuator and ground the other causing the doors to lock or unlock.

rear door hatch lock repair GMC Chevrolet - YouTube

? 4:26
https://www.youtube.com/watch?v=QS3PMhGgyAg
Apr 5, 2014 - Uploaded by auto resource
2002 Yukon, rear hatch lock not locking. ... rear door hatch lock repair GMC Chevrolet. auto resource ... chevy tahoe lift gate notopening - Duration: 2:12. ... A Method how to unlock your car in 10 seconds :) - Duration: 0:35.

chevy tahoe lift gate not opening - YouTube

? 2:12
https://www.youtube.com/watch?v=xU6ybiY3F4I
Sep 1, 2010 - Uploaded by 76bluemoon
Back lift gate/glass would not open or release. Even when unlocked with the key fob or the unlock switch on the drivers/passenger door. ... How To Install Replace Rear Lift Gate handle 2002-09 GMC Envoy Chevy Trailblazer ...

Lock/unlock motor may be failing. Remove the door panel and remove the connector from the lock motor. Check the dc voltage at the connector while pressing the lock switch. If you see battery voltage, replace the motor. If the voltage is low, inspect the wiring.

coulb be the control switch on your panel you can take the door panel off and check for loose connections and try to test for continuity. if you dont know how take it to a shop and have them diagnose the electrical. im quite sure it the switch that burnt out

Do the power windows work ? DDM - driver door module fuse 15 amp - location is the instrument panel fuse box , plus LT DR circuit breaker 25 amp. Circuit breakers rarely go bad . The power locks are controlled by electronic's .The passenger side has another power supply ,that's why they still work .
Door Lock System Components
The power door lock system consists of the following components:
• The driver door switch (DDS)
• The passenger door switch (PDS)
• The body control module (BCM)
• The driver information center (DIC)
• The rear door lock/unlock relay (LBEC)
• The reversible door lock actuators in each of the doors and liftgate

The front power door lock switches are integral components of the driver door module (DDS) and passenger door module (PDS). The switches are 2 position normally open rocker switches. When placed in either the lock or unlock positions, the switches provide a direct input to the DDS or PDS. The DDS or PDS monitors these inputs and sends a LAN message indicating a change in the switch's respective position. Modules which activate the power door lock motors receive the LAN message and activate the motor in the appropriate direction to lock or unlock the vehicle's doors and liftgate. The rear door lock switch provides a lock and unlock signal to the body control module (BCM). The BCM upon receipt of a lock or unlock signal will control the rear door lock/unlock relay and also send a LAN message to the DDS and PDS to perform the appropriate function.
The modules which activate the power lock motors are:
• The DDS (driver door lock actuator)
• The PDS (passenger front door lock actuator)
• The BCM (both rear door lock actuators and cargo door/liftgate)
The DDS and PDS are directly connected to the respective door lock actuator through the door lock motor lock and unlock circuits. Once a door lock or unlock request has been received, the module will supply battery voltage to one side of the actuator and ground the other causing the doors to lock or unlock.
The rear passenger and endgate doors are controlled by the BCM through the rear door lock/unlock relay which is incorporated onto the printed circuit board in the LH BEC. The BCM controls the unlock relay by providing ground to energize the coil and controls the lock relay by providing battery voltage to energize the relay coil. The energized the relay and allows voltage to be applied to either the door lock motor lock or unlock circuits. Since the other side of the door lock actuator is connected to the normally closed contacts of the opposing relay to ground, the doors lock or unlock.

It's possible you have broken wire or wires inside the flex boot from the body of the vehicle to the driver's door . This happens a lot .
Fuse Block - I/P instrument panel
Left of the I/P behind the side trim panel

is the child safety lock on?

Could be a relay for that door..
Or it could be the auto lock motor for that door.

Sounds like bad wiring, or bad door lock actuators. Check for power while locking/unlocking the doors.

This may be just a case of inadvertently hitting the window lock out n th driver door window switch by mistake. Check that first. Here's some background on window operation

Principles of Operation
The driver power window regulator motor is controlled directly by the master window/door lock/unlock switch (and its integrated "auto down" module). Power is supplied to the power window relay and the master window/door lock/unlock switch, and the passenger power window switch when the SEC/timer module grounds the coil side of the power window relay. The SEC/timer module will ground this relay when the ignition is in the ON position and will remain energized for approximately 15 minutes or until the driver or passenger door is opened.
The driver power window regulator motor is a reversible motor that is operated by applying power and ground to the motor leads to lower the window, and then reversing polarity on those leads to raise the window.
The passenger power window regulator motor is controlled directly by the passenger power window switch and can also be controlled by the master window/door lock/unlock switch. Power is supplied to the power window relay and the master window/door lock/unlock switch, and the passenger power window switch when the SEC/timer module grounds the coil side of the power window relay. The SEC/timer module will ground this relay when the ignition is in the ON position and will remain energized for approximately 15 minutes or until the driver or passenger door is opened.
The passenger power window regulator motor is a reversible motor, which is operated by applying power and ground to the motor leads to lower the window, and then reversing polarity on those leads to raise the window.
The power rear quarter glass is also directly controlled by the master window/door lock/unlock switch. The power rear quarter glass power latches also utilize reversible motors. The power rear quarter glass power latches are operated by applying power and ground to the motor leads to open the window, and then reversing polarity on those same leads to close the window.
Symptom Chart Condition Possible Sources Action

• All windows are inoperative

• BJB Fuse:
  • F20.
• Circuit.
• Power window relay.
• Front door power window switch.

• GO to Pinpoint Test A .

• Single power window is inoperative

• Front door power window switch.
• Front door power window regulator.
• Circuit.
• Driver door power window switch.

• GO to Pinpoint Test B .

• Vent power window is inoperative — quarter window glass power latch

• Circuit.
• Quarter window glass switch.
• Quarter window glass power latch.

• GO to Pinpoint Test C .

• The one touch down feature is inoperative

• Master window regulator and door lock switch.

• INSTALL a new master window/door lock/unlock switch. REFER to Switch—Master Window Door Lock/Unlock .

• The back window will not defrost

• CJB Fuses:
  • F30 (10A).
  • F32 (20A).
  • F34 (20A).
• BJB Fuse:
  • F27 (45A)
• Circuit.
• Heated back window switch.
• SEC/timer module.
• Rear window defrost relay.

• GO to Pinpoint Test D .

• The back window defrost will not shut off automatically

• SEC/timer module.
• Circuit.
• Rear window defrost relay.

• GO to Pinpoint Test E .