Power windows passenger side, rear, and lift gate will not unlock

Door Lock System Components
The power door lock system consists of the following components:
• Driver Door Module (DDM)
• Passenger Door Module (PDM)
• Liftgate Module (LGM)
• Door lock relay
• Door unlock relay
• Body Control Module (BCM)
• Reversible door lock actuators in each of the doors
• LR/RR LOCKS 10A fuse (relay supply voltage)
• Door lock switches in driver and passenger doors (switches are integral components to the DDM and PDM)

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).

Could be a lot of thing's causing it not to work . The way we would diagnose is to hook up a scan tool an look for a DTC - diagnostic trouble code in the lift gate control module first ,no codes ,look at a wiring diagram an test voltages at the lock actuator ,switch etc... Also look on scan tool data to see if the lock/unlock command is getting to the lift gate module .

In this link it explains how the drivers side cylinder lifts and lowers the lift gate. The passenger side just hold the gate in the open position. If the lift gate will not stay open the passenger side cylinder is probably bad

https://www.youtube.com/watch?v=PSbpMU09aZU

One fuse powers all door lock actuators . The other door locks work ? if so it's not a fues problem .
The following locking functions are included on the vehicle:
• All the doors unlock -- All the doors will unlock, including the endgate/liftgate, when any power door unlock switch is detected. The passenger doors lock directly by pressing the lock switches. The driver door unlocks by the BCM using a driver door unlock relay.
• All the doors lock -- All the doors will lock, including the endgate/liftgate, when any power door lock switch is activated. All the lock actuators will activate directly from the power door lock switch (external to the BCM).
• The end/lift gate lock switch -- All the doors will lock or unlock from the end/lift gate lock switch

You probably have a bad lock actuator

Here is how it works !
Liftgate Locking Operation
The lift gate will lock any time the vehicle is shifted out of park on vehicles equipped with an automatic transmission and at vehicle speeds exceeding 5 kph with manual transmission. This happens in conjunction with auto door locks if enabled or independently of auto door locks if the feature is disabled. This ensures that the lift gate is locked anytime the vehicle is shifted out of park or when the vehicle is in motion.
The lift gate lock relay supply and coil sides receive a constant voltage through the battery voltage supply circuit and the ECC fuse. The normally closed contact is connected to ground and the control side is connected to the body control module (BCM). A lock function will occur when a door lock switch activation, keyless entry lock transmission, auto door lock function or a lift gate lock function has been received by the BCM. The BCM will then ground the control side of the lift gate lock relay. This energizes the relay and allows voltage to be applied to the lift gate lock actuator lock control circuit. Since the other side of the lift gate lock actuator is connected to the normally closed contacts of the door unlock relay to ground, the lift gate will lock. When an unlock function occurs the BCM will ground the control side of the unlock relay and the rear doors and lift gate will unlock.
The BCM also runs diagnostics on the lift gate lock relay control circuit and will set DTC B3825 as current and also send a Class 2 message to the DIC. The DIC will display REPLACE LIFTGATE FUSE to inform the driver that a fault has been detected in the lift gate lock circuit and that the lift gate is not locked. Faults that will set the DTC and cause the DIC to display the message could be any of the following:
?€¢
An open ECC fuse

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An open or short to ground in the lift gate lock relay battery positive voltage circuit

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A faulty lift gate lock relay

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An open or short to ground in the lift gate lock relay control circuit

?€¢
A short to ground in the lift gate lock actuator lock control circuit

?€¢
A faulty BCM

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 ...

it will only open when the key is in the ignition and turned on !!

It can be faulty switch or its issue with lift gate latch.Its got stuck up hard or cracked inside.It has to be inspected.-----------
There are few help links with proper solutions for these problem.I suggest you to refer the links.
Click the link below:----
2007 Mercury Mountaineer: Liftgate will not Unlock or Open? http://whoisbyme.blogspot.in/2012/06/2007-mercury-mountaineer-liftgate-will.html
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Adjust Hydraulic Lifters? http://schematicsdiagram.blogspot.in/2012/04/adjust-hydraulic-lifters.html
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How to open rear lift gate? http://repairhelpcenter.blogspot.com/2011/12/how-to-open-rear-lift-gate.html

--------- Power Liftgate Shuts Down http://whoisbyme.blogspot.in/2012/07/power-liftgate-shuts-down.html
------------ Power Lift Gate Will Not Remain Open http://whoisbyme.blogspot.in/2012/07/power-lift-gate-will-not-remain-open.html
----------- Power Lift-gate will not Operate http://whoisbyme.blogspot.in/2012/07/power-lift-gate-will-not-operate.html
------------- Liftgate will Not Stay Up Open? http://whoisbyme.blogspot.in/2012/07/liftgate-will-not-stay-up-open.html

---------------- Rear Door will not open http://whoisbyme.blogspot.in/2012/07/rear-door-will-not-open.html
------------ 2000 Toyota Corolla: Rear Door wont open from outside or inside? http://whatisbyme.blogspot.in/2012/05/2000-toyota-corolla-rear-door-wont-open.html

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These details will help.
Thanks.

They are not related ...
The lift gate locking mechanism can be accessed by removing the interir trim pannel on the gate ... and locating the locking actuator and replacing it...
The same can be done for the power window motor ... remove the interior trim panel and replace the power window motor...

Hope I helped !!

both the rear passenger side wont unlock ???? How many doors are on the passenger side ? Or both back doors don't unlock ? Two relays lock / unlock the back door's Not the lift gate . The BCM controls the relay's . The relay's are located in the rear fuse box . Under back seat .

Replace the door lock / unlock relay in the fuse box next to the driver side door. no problem since than.