Rear cargo door stopped working

Service repair info. manual would be the place to start ,seeing how you have no clue .,or maybe a qualified repair shop. How are you going to fix it with out knowledge of how it works an what to check , --------------------------------------------------------------------------------
Power Door Locks Circuit Description
The power door locks are operated by reversible motors. The motors are found in the following locations:
• In each front door
• The side door
• The rear door
The PWR ACCY circuit breaker (30A) supplies voltage to the door lock motors.
If you move either power door lock switch, mounted in the front doors, the LOCK applies voltage to cavity F of the door lock relay. This energizes the lock coil in the relay. Current then flows through CKT 295 (GRY) directly to the following components:
• Both front door lock motors
• The side door lock motor
• The rear door lock motor (cargo doors only)
CKT 246/294 (TAN) provides the ground for the motors. The normally closed contacts of the UNLOCK then contacts the door lock relay.
If you move one of the door lock switches to UNLOCK the polarity of the system reverses. Current flows through the energized UNLOCK relay contacts. The LOCK relay contacts provide ground.
When the UNLOCK button is pressed once on the RKE transmitter, only the driver door unlocks. If it is pressed a second time within 5 seconds, all doors unlock.
If the side door is open, the side door jamb switch ground signal is opened/broken. If you move the door lock switch to LOCK while the side door is open, the following actions occur:
• The 2 front doors lock
• The rear door locks (cargo doors only)
When you close the side door, the door jamb switch closes. This closes the ground signal to the body control module {CKT 775 (PNK)}. A 5 second timer then starts in the module. After 5 seconds, cavity A4 connector C1 of the body control module supplies voltage to the door lock relay via CKT 195 (LT BLU). This energizes the door lock relay, which sends voltage to the door lock motors in order to lock the side door. Refer to Door Jamb Switches, Liftgate Strut Switch for a schematic of all door jamb switch inputs.
If the side door opens during this 5 seconds, the 5 seconds timer is reset. The locking pulse takes place at the end of the 5 seconds. Unlocking the door resets the 5 second timer in the body control module.
Use the following components in order to unlock the door lock system:
• The LH power door lock switch
• The RH power door lock switch
On vehicles equipped with cargo doors, the cargo door opener mechanically opens the door once the door lock system is unlocked. On vehicle equipped with a liftgate, the liftgate lock/unlock release switch (mechanical key) is added in order to serve the same function as the front power door lock switches. These functions locking and unlocking all doors, including the liftgate. Once the door lock system is unlocked, press the liftgate release switch in order to electrically open the liftgate and pull the handle in order to open the secondary latch.

LOCKING AND UNLOCKING
You can use the power door lock control or the remote control to lock and unlock your doors and tailgate.See Tailgate Lock.
Power Door Locks
The power door lock control is on the driver and front passenger door panels.

AUnlock.
BLock. Remote Control
You can use the remote control at any time your vehicle is not running.
Unlocking the Vehicle (Two-Stage Unlock)
Press the button to unlock the driver door. Press the button again within three seconds to unlock all doors.The direction indicators flash. The direction indicators flash twice to confirm the change. The unlocking mode applies to the remote control, keyless entry keypad and intelligent access.
Press and hold both the lock and unlock buttons on the remote control for four seconds to disable or enable two-stage unlocking. Disabling two-stage unlocking allows your entire vehicle to unlock with one press of the button.
Intelligent access at the driver door unlocks your entire vehicle when you disable two-stage unlocking.
Locking the Vehicle
Press the button to lock all doors.The direction indicators flash.
Press the button again within three seconds to confirm that all the doors are closed.The doors lock again, the horn sounds and the direction indicators flash if all the doors are closed.
Mislock
If any door is open, or if the hood is open on vehicles with an anti-theft alarm or remote start, the horn sounds twice and the direction indicators do not flash.
Activating Intelligent Access
General Information
You can unlock and lock the vehicle without taking the keys out of your pocket or purse when your intelligent access key is within 3 ft (1 m) of your vehicle. Intelligent access uses a sensor on the back of the door handle for unlocking and a separate sensor on the face of each door handle for locking.
The system does not function if:

• Your vehicle battery has no charge.
• The key battery has no charge.
• The key frequencies are jammed.

Note: The system may not function if the key is close to metal objects or electronic devices, for example keys or a cell phone.
Note: If the system does not function, use the key blade to lock and unlock your vehicle. See Remote Control.
Unlocking Using Intelligent Access
With your intelligent access key within 3 ft (1 m) of your vehicle, touch the unlock sensor on the back of the door handle for a brief period and then pull on the door handle to unlock, being careful to not touch the lock sensor at the same time or pulling the door handle too quickly. The intelligent access system requires a brief delay to authenticate your intelligent access key fob.
Locking Using Intelligent Access
With your intelligent access key within 3 ft (1 m) of your vehicle, touch the outer door handle lock sensor for approximately one second to lock, being careful to not touch the unlock sensor on the back of the door handle at the same time. After locking, you can immediately pull on the door handle to confirm locking occurred without inadvertently unlocking.
Note: Do not use the outside door handle as a roof cargo strap.
At the Electronic Tailgate (If Equipped)
Press the exterior tailgate release button inside of the tailgate handle. The tailgate unlocks and opens. See Electronic Tailgate.
Smart Unlock
This feature helps to prevent you from locking your intelligent access key inside your vehicle's passenger compartment or rear cargo area.
If you leave your key in the ignition, when you open the driver door and lock your vehicle with the power door lock control, the doors lock then unlock.
You can still lock your vehicle with the key in the ignition by:

• Using the manual lock on the inside of the door.
• Locking the driver door with a key.
• Using the keyless entry keypad.
• Using the lock button on the remote control.

Smart Unlocks for Intelligent Access Keys
This feature helps to prevent you from locking your intelligent access key inside your vehicle's passenger compartment or rear cargo area.
When you lock your vehicle using the power door lock control (with the door open, vehicle in park and ignition off), your vehicle searches for an intelligent access key in the passenger compartment after you close the door. If your vehicle finds a key, all of the doors immediately unlock.
In order to override the smart unlock feature and intentionally lock the intelligent access key inside your vehicle, you can lock your vehicle after all doors are closed by using the keyless entry keypad, pressing the lock button on another intelligent access key or touching the locking area on the handle with another intelligent access key in your hand.
When you open one of the front doors and lock your vehicle using the power door lock control, all doors lock then unlock if the ignition is on.
Autolock
Autolock locks all the doors when:

• All doors are closed.
• The ignition is on.
• You shift into any gear putting your vehicle in motion.
• Your vehicle reaches a speed greater than 12 mph (20 km/h).

Autolock repeats when:

• You open then close any door while the ignition is on and your vehicle speed is 9 mph (15 km/h) or lower.
• Your vehicle reaches a speed greater than 12 mph (20 km/h).

Autounlock
Autounlock unlocks all the doors when:

• The ignition is on, all the doors are closed, and your vehicle has been moving at a speed greater than 12 mph (20 km/h).
• Your vehicle comes to a stop and you switch the ignition off or to the accessory position.
• You open the driver door within 10 minutes of switching the ignition off or to accessory.

Note: The doors do not autounlock if you electronically lock your vehicle after you switch the ignition off and before you open the driver door.
Enabling or Disabling Autounlock
You can enable or disable the autounlock feature in the information display or an authorized dealer can do it for you. See General Information.
Illuminated Entry
The interior lamps and select exterior lamps illuminate when you unlock the doors with the remote entry system.
The illuminated entry system turns off the lights if:

• The ignition is on.
• You press the remote control lock button.
• After 25 seconds of illumination.

The dome lamp does not turn on if the control is set to the off position.
The lights do not turn off if:

• You switch them on with the dimmer control.
• Any door is open.

Battery Saver
The battery saver turns off the interior lamps 30 minutes after you switch off the ignition if a door is open and the dome lamp switch is on. It turns off the interior lamps after 10 minutes if the dome lamp switch is off.
Accessory Mode Battery Saver for Intelligent Access Keys (If Equipped)
If you leave the ignition on after leaving your vehicle, it turns off 15 minutes after you close all of the doors.

first is fuses are they good.?
the locks on cars are solenoids.
im guessing all ways to open it fail,
keys, key fobs, and internal controls panels?
no childern locks set (some are hidden on cars)
no drivers, panel , master lock, he pushes it and all locks freeze?
this is a general statement.
so you use a thing like a volt meter. $10 at walfart.
we check for 12vdc across the 2 solenoids.
12vdc when active is good.
0v is bad,
if you get 12v then the solenoid is bad or jammed.
if you get 0v, the controls are bad.
its that simple. and electro magnetic solenoid, is easy to test.
with any voltmeter made.
if the controls are bad we use the same method to check them.
12vdc to the switch it must be.
then you push the rear switch and 12vdc leaves this switch.
if not the switch is bad.(input good)

How are you trying to open the door , button on key fob ? With this system you can pull up on the drivers handle an it activates Antennas in the external side door handles (C30/C70 front doors, S40/V50 rear doors)

Antennas in the passenger compartment and cargo compartment

An antenna in the rear bumper

Quick lock motors in the lock units in the side doors

The remote keyless entry (RKE) receiver receives a signal from the key

The switch in the clutch pedal (manual transmissions) or a signal from the brake pedal switch via the central electronic module (CEM) (automatic transmissions)

Key-in switch.

Switch in door handle and lock button on handle .
If a door handle is pulled outward, a switch closes that wakes up the system and activates the antennas in the handles on the side where the handle has been pulled out. If a valid key is within a radius of approx. 1.5 metres from the handle, the relevant door will open and the vehicle will unlock one or several doors. Which doors are unlocked depends on the settings for the system. The vehicle can also be unlocked if the handle is affected on the tailgate.

Taking your vehicle to a qualified repair shop instead of mess with thing's you have no clue about ,is what you should have done . Replacing BCM'S - needs to be programmed .
If the body control module (BCM) is replaced, the following procedures must be performed in the following order:
BCM reprogramming--Refer to Body Control Module (BCM) Programming/RPO Configuration in Computer/Integrating Systems.
Theft learn--Refer to Programming Theft Deterrent System Components in Theft Deterrent. A new BCM will learn the Passlock™ information automatically but the powertrain control module (PCM) must still learn the theft information from the BCM.

Plus the bcm has nothing to do with the power window's DDM -the driver door module controls the window .
Programmable Automatic Door Locks
The automatic door lock feature can be programmed to control the door lock system. The automatic door lock feature is factory programmed to have all doors lock and unlock. For detailed instructions on programming the automatic door locks, refer to Vehicle Personalization in Personalization.
When the automatic door lock feature is programmed to control the door lock system, the driver door module (DDM), passenger door module (PDM) and body control module (BCM) will lock the vehicle doors if the following inputs are true:
• Ignition 1 input is active.
• All door jamb switch inputs are inactive.
• Cargo door or liftgate/liftglass ajar inputs are inactive.
• Transmission is shifted out of park.
This automatic door lock function will only occur once per ignition cycle unless, a door jamb switch input changes state to active and back to inactive. Then the DDM, PDM and BCM will lock all doors again.
Once the automatic door lock feature has locked the doors, the BCM will then unlock all the doors when the transmission is shifted into park.
Before replace these componets hooking up a factory scan tool an checking data input's an DTC'S - diagnostic trouble codes .

key is manual lock and electric assisted unlock . charge the battery with red screw on fuse panel Use key to unlock turning to rear.
Place key in ignition then turn on and off 8 times leaving it in on position until it beeps approx 5 sec then press any button on the key and turn ignition off.

its alot going on if all that started happening at one time check the bcm. body control module.

The power windows an power locks are controlled by a module , DDM - driver door module . As far as the locks locking when you put the vehicle into reverse an unlocking when you put the vehicle into park , that's how there are suppose to work , automatic lock an unlock feature . When you put the vehicle into any gear from park the locks should lock . Did she hit window lockout function ?

The power door lock system consists of the following components:
• The driver door module (DDM)
• The passenger door module (PDM)
• The body control module (BCM)
• The driver information center (DIC)
• The rear door lock switch
• The door lock relay
• The door unlock relay
• The liftgate lock relay--utility vehicles with liftgate only
• The reversible door lock actuators in each of the doors and liftgate
• LOCKS 20A fuse (rear lock/unlock relay supply voltage)
• ECC 10A fuse (liftgate lock relay supply voltage .

Programmable Automatic Door Locks
The automatic door lock feature can be programmed to control the door lock system. The automatic door lock feature is factory programmed to have all doors lock and unlock. For detailed instructions on programming the automatic door locks, refer to Vehicle Personalization in Personalization.
When the automatic door lock feature is programmed to control the door lock system, the driver door module (DDM), passenger door module (PDM) and body control module (BCM) will lock the vehicle doors if the following inputs are true:
• Ignition 1 input is active.
• All door jamb switch inputs are inactive.
• Cargo door or liftgate/liftglass ajar inputs are inactive.
• Transmission is shifted out of park.
This automatic door lock function will only occur once per ignition cycle unless, a door jamb switch input changes state to active and back to inactive. Then the DDM, PDM and BCM will lock all doors again.
Once the automatic door lock feature has locked the doors, the BCM will then unlock all the doors when the transmission is shifted into park.
Driver, Passenger and Cargo Door 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 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 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 relays and also send a Class 2 message to the DDM and PDM to perform the appropriate function.
The modules which activate the power lock motors are:
• The DDM (driver door lock actuator).
• The PDM (passenger front door lock actuator).
• The BCM (both rear door lock actuators and cargo door/liftgate).
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 and cargo doors differ slightly in that they use lock and unlock relays. The relays supply and coil sides receive a constant voltage through the battery voltage supply circuit. The normally closed contacts are connected to ground and the control side is connected to the BCM. Once a door lock or unlock request has been received by the BCM, the BCM will ground the control side of the appropriate relay. 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.

Power Door Locks Circuit Description
The power door lock system incorporates door lock switches on both front doors and on the RH D-pillar, door lock motors in all passenger doors and in the RR cargo door, a door lock relay and a door lock control module.
Power for the door lock switches and the door lock control module is supplied from the CIG LTR fuse 13 through CKT 640 (ORN). Power for the door lock relay is supplied from the PWR ACCY circuit breaker through CKT 540 (ORN). Ground for the door lock relay is supplied from G202 through CKT 150 (BLK) and ground for the door lock control module is supplied from G400 through CKT 150 (BLK).
The door lock motors are reversible and both sides are connected to the normally closed contacts of the door lock relay. Those contacts of the relay are connected to G202. When any of the door lock switches are placed in the lock position, voltage is supplied through CKT 195 (LT BLU) to the relay lock coil. Since the other side of the lock coil is connected to ground, the coil is energized and it pulls the lock contacts closed. Voltage is then supplied through CKT 295 (GRY) to all the door lock motors and the doors lock. The unlock function operates in much the same manner except that when any of the switches are placed in the unlock position, voltage is supplied through CKT 194 (WHT) to the unlock coil of the relay and CKT 294 (TAN) supplies voltage to the apposite side of the door lock motor and the doors unlock.
Door Lock Control Module Description
The door lock control module is used on vehicles equipped with cargo doors. The purpose of the module is to lock the cargo doors after a lock cycle has been commanded from any of the door lock switches with the cargo doors open. When the RH cargo door is open, the module receives a ground signal from the closed contacts of the rear door jamb switch on CKT 1897 (ORN/BLK) to G400. When a lock command is received, the module retains this input until it receives an open input from the rear door jamb switch. Then the module sends a lock command through CKT 194 (WHT) to the door lock relay and the doors lock.
Rear Cargo Doors Description
The power door lock motor will not operate unless the rear cargo doors are fully closed. The power door lock motor is in the right cargo door. The contactors are on the rear cargo door opening on the body and on the right cargo door.

There is a flash for the body control module for this problem. You need to go to the dealership to get it performed though.