Rear door. Rear Off side door will not unlock.

The most likely culprit is a faulty actuator. You can test this by having someone activate the rear hatch while listening for a click or sound of some sort. If there is sound but no opening, it indicates a bad latch actuator. If there is no noise, it could be a fuse or wiring issue. You can manually unlock the door by removing the trim, but be careful around the glass latch as there are 2 push pins.

https://www.autogenius.info/chevrolet-suburban-2006-fuse-box-diagram-2/


Check the wiring in the boot that runs from the body to the top of the liftgate for broken wires.

You might have to take it to a collision shop. Remove the rear hatch panel to gain access to the latch assembly if it's not responding. If you can't get it open, take it to a collision shop as they deal with these kinds of things regularly.

Since the driver's door gets the most use, and all circuits run through the master switch, check driver's door first and check the wiring at the hinge area for breaks.

You may get some ideas on You Tube.
Check out the link and look at the thumbnails on the right for further ideas

98 Honda civic rear door handle and child safety lock fix

I vote for corroded or loose cable inside door.

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

Many rear doors have a child safety lever to keep the rear doors from unlocking. This lever will be located on the rear edge of the door and you can switch it to unlock those doors with the others. If you have the owner's manual it will give you directions, if not check with a dealer as they can tell you the procedure.

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 .

I had the same problem on the rear door of my 1998 528i and it was the door actuator that had gone bad. I had to take the rear seat out to get the door panel off. Once I had the door panel off it was not that difficult to replace the door actuator.

sounds like that rear door lock will also not unlock with the switch either, correct ? It might lock , but not unlock. Door lock actuator needs to be replaced.

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