Rear liftgate Keeps popping open even after it closes

Rear hatch ??? power liftgate or just won't unlock ?

Power Liftgate System Components
The power liftgate system includes the following components:
• Liftgate motor assembly
• Liftgate latch
• Liftgate module
• Liftgate side upper sensor - left
• Liftgate side upper sensor - right
• Liftgate handle switch
• Liftgate close switch

Did you check for DTC'S - diagnostic trouble codes in the liftgate control module ? do you know what I'm talking about ?

go see a local mechanic .

Power Liftgate System Components
• Liftgate motor assembly
• Liftgate latch
• Liftgate module (LGM)
• Liftgate side upper sensor - left
• Liftgate side upper sensor - right
• Liftgate handle switch
• Liftgate close switch
• GMLAN serial data link
• PWR LIFT GATE 30 amp fuse
• PLG 10 amp mini-fuse

Power Liftgate System Description
Liftgate Module
The liftgate module controls the liftgate motor, liftgate clutch, and liftgate latch based on various inputs. The liftgate module also performs diagnostics on these inputs and outputs and will disable liftgate functionality and set DTCs should a fault be detected. The liftgate module is secured to the motor assembly at the left rear of the vehicle. The module requires a liftgate position learn procedure be performed when replacing. This allows the module to learn the full open and full closed positions of the liftgate.

Location - fuse block right rear
Fuse Block - Right Rear
In the passenger compartment, near the right side of the rear seat cushion under the carpet

Does it have a power lift gate ? Do you know anything about automotive electrical systems ? How to use a wiring diagram along with a digital volt ohmmeter to test electrical circuits . ?
Power Liftgate
The power liftgate feature will allow the customer to automatically open or close the liftgate by activating the interior open/close switch, the remote keyless entry transmitter, or by manually initiating liftgate movement. The power liftgate uses a power cinch system to latch the liftgate.
The power liftgate system consists of:

• Power liftgate control switch (located in the overhead console)
• Power liftgate motors (located in the rear headliner area)
• Optical sensor and power liftgate encoder wheel (located in the left power liftgate motor assembly)
• Pinch strip switches (located on the body by the liftgate)
• Home position switch (located on the cinch actuator)
• Forkbolt switch (located on the cinching latch assembly)
• Detent switch (located on the cinching latch assembly)
• Liftgate close chime module (located in a unit external from the power liftgate module)

The forkbolt and detent switch are located on the cinch latch assembly and the home position switch is located on the cinch actuator assembly. For information on removal of the latch or cinch actuator assembly, refer to Section 501-14 .
The power liftgate may not operate under the following conditions:

• a low voltage or dead battery.
• a disconnected battery.
• a power liftgate that has been left open for more than six hours.
• a power liftgate that has been manually closed and left ajar.

If any of these conditions has occurred, the power liftgate must be reset before performing any pinpoint tests. For additional information, refer to Power Liftgate Initialization .

Power Liftgate Initialization NOTE: If the power liftgate system is turned OFF in the message center, the system cannot be activated with any switches or with the liftgate handle. The system will need to be turned ON for any power operation to occur.
NOTE: The power liftgate may not operate under the following conditions:

• a low voltage or dead battery.
• a disconnected battery
• a power liftgate that has been left open for more than six hours.
• a power liftgate that has been manually closed and left ajar.

If any of these conditions has occurred, the power liftgate must be reset.

1. Manually close and fully latch the power liftgate.

1. NOTE: If the power liftgate does not open during this step, refer to the symptom chart to diagnose the power liftgate for no operation. Power open the power liftgate by using the keyfob or overhead console switch.

1. Once the power liftgate is fully open, close the power liftgate by using the keyfob or overhead console switch.
2. your best bet mite be to have a qualified repair shop check it out .

Door ajar switch possibly . The lift gate not working is a different matter . Could be any number of thing's .
Power Liftgate System Components
• Liftgate motor assembly
• Liftgate latch
• Liftgate module (LGM)
• Liftgate side upper sensor - left
• Liftgate side upper sensor - right
• Liftgate handle switch
• Liftgate close switch
• GMLAN serial data link
• PWR LIFT GATE 30 amp fuse
• PLG 10 amp mini-fuse

Your best bet take it to a qualified repair shop that has the diagnostic tool that can communicate with the lift gate control module , too check for DTC'S - diagnostic trouble code's .
Liftgate Module
The liftgate module controls the liftgate motor, liftgate clutch, and liftgate latch based on various inputs. The liftgate module also performs diagnostics on these inputs and outputs and will disable liftgate functionality and set DTCs should a fault be detected. The liftgate module is secured to the motor assembly at the left rear of the vehicle. The module requires a liftgate position learn procedure be performed when replacing. This allows the module to learn the full open and full closed positions of the liftgate.

DTC B153A 00: Liftgate Latch Switch Signal Circuit
DTC B153A 08: Liftgate Latch Switch Signal Circuit Signal Invalid
DTC B153B 02: Liftgate Open Switch Signal Circuit Short to Ground
DTC B153B 05: Liftgate Open Switch Signal Circuit Open
DTC B153E 02: Liftgate Position Sensor Signal Circuit Short to Ground
DTC B153E 05: Liftgate Position Sensor Signal Circuit Short to Battery or Open
DTC B153E 08: Liftgate Position Sensor Signal Circuit Signal Invalid

This is not a job for a diy'er or vehicle owner .

Sensor problem , take an have liftgate control module checked for DTC'S - diagnostic trouble code's . Do you know what DTC'S are ?

Rear Hatch/Gate Description and Operation
Operation
A power open or close cycle can only be initiated from the fully closed or open positions while the vehicle is in park and the liftglass ajar switch input to the liftgate module is inactive. At any time during a power open or close cycle the operation can be reversed by pressing any of the open/close switches. The power liftgate can be switched to manual mode with the on/off switch in the overhead console and during manual operation the power latch will still operate. During power liftgate operation the liftgate module continuously monitors the liftgate position and load profile. The position is calculated from hall effect sensor counts and the electrical load of the gear motor is used to determine physical resistance to the liftgate. Both of these profiles must be learned before the liftgate can operate properly and relearned any time most liftgate components are serviced.

Object Obstruction Detection
The liftgate control module continuously monitors power liftgate operation and calculates its location and direction of travel using 2 hall effect sensors that are part of the gear motor assembly. The hall effect sensors are 3 wire sensors and are supplied with a 5 volt power circuit, ground and signal circuits from the liftgate control module. The hall effect sensor signal circuits are referenced from battery voltage within the liftgate control module and pulsed low by the hall effect sensors.
The power liftgate system uses a secondary object detection method which consists of object sensors fixed to both sides of the liftgate near the seal area. The object sensors consist of an internal fixed resistor and normally open switch contacts which when closed will bypass the resistor. The signal circuit is supplied 5 volts through a resistor and monitored within the liftgate control module, and during normal power liftgate operation the signal circuit should remain a fixed value. When an object presses one of the sensors the contacts close and the resistor is bypassed causing the signal circuit voltage at the module to go low.
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Diagnostic Instructions
• Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
• Review Strategy Based Diagnosis for an overview of the diagnostic approach.
• Diagnostic Procedure Instructions provides an overview of each diagnostic category.
DTC Descriptor
DTC B1019 00: System Configuration Error
Circuit/System Description
When calibrating the liftgate position, the liftgate module (LGM) is placed in a functional state to learn the liftgate travel limits. DTC B1019 00 will set automatically as an indicator that the system is in learn mode and not as a fault indicator. Once the travel limits are learned by the liftgate module, the LGM will exit calibration mode. If the LGM does not exit learn mode, DTC B1019 00 will remain current and indicate a fault.

DTC B153B 02: Liftgate Open Switch Signal Circuit Short to Ground
DTC B153B 05: Liftgate Open Switch Signal Circuit Short to Short to Battery or Open

DTC B153E 02: Liftgate Position Sensor Signal Circuit Short to Ground
DTC B153E 05: Liftgate Position Sensor Signal Circuit Short to Battery or Open
DTC B153E 08: Liftgate Position Sensor Signal Circuit Signal Invalid

DTC B153F 02: Liftgate Object Sensor Signal Circuit Short to Ground
DTC B153F 03: Liftgate Object Sensor Signal Circuit Voltage Below Treshold
DTC B153F 05: Liftgate Object Sensor Signal Circuit Short to Battery or Open
DTC B153F 07: Liftgate Object Sensor Signal Circuit Voltage Above Threshold

Unless you have electrical diagnostic skills , I suggest you take this to the dealer ! The lift gate can be opened by operating the switch on the instrument panel. Battery voltage is supplied to the liftgate actuator through the body control module (BCM). The BCM will pulse the lift gate actuator when a release input is received through the key fob, or the instrument panel switch.
The body control module (BCM) receives an input from the liftgate ajar assembly. The ajar assembly is normally open when the liftgate is fully closed. When the liftgate is opened, the ajar assembly contacts close providing a path to ground. The driver information center (DIC) illuminates the rear access open message when the gate is open. The instrument panel cluster (IPC) receives a serial data message from the BCM indicating the liftgate ajar status. If this message is displayed and the vehicle speed is greater than 8 km/h (5 mph), a chime will sound.
It could be ajar switch is bad .

the hinged glass out....
the fsm factory serv. man. shows this.

chapter 23 , called heated rear glass.
page130 states
Disconnect heated liftgate glass electrical connector2. Open the liftgate and support.
3. Disconnect liftgate hydraulic cylinders (3) at the lower ball studs.
4. Close liftgate, but not latch in the closed position.
5. Remove hinge covers (1) and remove honge bolts (2).
6. Remove liftgate. unquote...

Operation
A power open or close cycle can only be initiated from the fully closed or open positions while the vehicle is in park and the liftglass ajar switch input to the liftgate module is inactive. At any time during a power open or close cycle the operation can be reversed by pressing any of the open/close switches. The power liftgate can be switched to manual mode with the on/off switch in the overhead console and during manual operation the power latch will still operate. During power liftgate operation the liftgate module continuously monitors the liftgate position and load profile. The position is calculated from hall effect sensor counts and the electrical load of the gear motor is used to determine physical resistance to the liftgate. Both of these profiles must be learned before the liftgate can operate properly and relearned any time most liftgate components are serviced.


Object Obstruction Detection
The liftgate control module continuously monitors power liftgate operation and calculates its location and direction of travel using 2 hall effect sensors that are part of the gear motor assembly. The hall effect sensors are 3 wire sensors and are supplied with a 5 volt power circuit, ground and signal circuits from the liftgate control module. The hall effect sensor signal circuits are referenced from battery voltage within the liftgate control module and pulsed low by the hall effect sensors.
The power liftgate system uses a secondary object detection method which consists of object sensors fixed to both sides of the liftgate near the seal area. The object sensors consist of an internal fixed resistor and normally open switch contacts which when closed will bypass the resistor. The signal circuit is supplied 5 volts through a resistor and monitored within the liftgate control module, and during normal power liftgate operation the signal circuit should remain a fixed value. When an object presses one of the sensors the contacts close and the resistor is bypassed causing the signal circuit voltage at the module to go low.

Gear Motor Assembly
The liftgate motor is a bi-directional motor and open or close operation is the result of the direction of the motor rotation. The liftgate module controls the liftgate motor through the control circuits by suppling power and ground in the appropriate polarity. The motor control circuits are monitored by the liftgate module prior to activation for a high or low condition and during motor operation for any irregular current flow conditions.
The liftgate motor clutch engages or disengages the liftgate motor to the liftgate drive gear and is the component that determines power or manual operation. When the liftgate module supplies power to the clutch control circuit the clutch coil is energized and the liftgate motor is engaged to the liftgate drive gear so that power operation can occur. The liftgate module monitors the clutch control circuit at all times for a short high while in an inactive state or a short low or insufficient current flow while in an active state.
The full open switch is part of the gear motor assembly and will close and become active when the liftgate reaches the full open position. The full open switch signal circuit is supplied battery voltage through a resistor and monitored within the liftgate module. The liftgate provides a low reference circuit and when the switch contacts close the signal circuit goes low and the liftgate module determines the switch to be active.

DTC B153A 00: Liftgate Latch Switch Signal Circuit
DTC B153A 08: Liftgate Latch Switch Signal Circuit Signal Invalid

When calibrating the liftgate position, the liftgate module (LGM) is placed in a functional state to learn the liftgate travel limits. DTC B1019 00 will set automatically as an indicator that the system is in learn mode and not as a fault indicator. Once the travel limits are learned by the liftgate module, the LGM will exit calibration mode. If the LGM does not exit learn mode, DTC B1019 00 will remain current and indicate a fault.
DTC B153B 02: Liftgate Open Switch Signal Circuit Short to Ground
DTC B153B 05: Liftgate Open Switch Signal Circuit Short to Short to Battery or Open
DTC B153E 02: Liftgate Position Sensor Signal Circuit Short to Ground
DTC B153E 05: Liftgate Position Sensor Signal Circuit Short to Battery or Open
DTC B153E 08: Liftgate Position Sensor Signal Circuit Signal Invalid

Your best bet , take it to the dealer .

The easy part is you just need the latch for the liftgate. The hard part is getting to it and opening the liftgate to replace the latch. You should be able to pull the liftgate trim off most of the way with the gate closed and try to manually actuate the latch to open the gate. You may have to go so far as breaking the latch from the inside to open the gate and then replace your latch.