06 Lincoln Navigator liftgate opens okay but need help to close why?

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 the following:

• 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)
• There are a lot of electrical switches an motors
• Visual Inspection Chart Mechanical Electrical
  • Power liftgate motors
  • Power cinching latch and linkage
  • Power liftgate pinch strip switches
  • Liftgate and liftgate hinges
  • Liftgate assist cylinders
  • Liftgate strikers
  • Exterior release handle and linkage
  • Liftgate weatherstrip
  • Liftgate alignment to body and striker
  • Central junction box (CJB) fuse:
    • 5 (7.5A)
    • 105 (30A)
  • Power liftgate control switch
  • Wiring harness
  • Connectors
  Are you willing to take the back hatch apart to test this ,to find a fix . But first have it check for DTC'S - diagnostic troulbe codes '
• Power Liftgate Module Diagnostic Trouble Code (DTC) Index
  Power Liftgate Module Diagnostic Trouble Code (DTC) Index DTC Description Source Action B1342 ECU Is Defective Power Liftgate Module INSTALL a new power liftgate module. REFER to Power Liftgate Module in this section. B2477 Module Configuration Failure Power Liftgate Module REFER to Section 418-01 . B2522 Vbatt1 Circuit Failure Power Liftgate Module Go To Pinpoint Test B . B2552 Vbatt2 Circuit Open Power Liftgate Module Go To Pinpoint Test B . B2698 Vbatt2 Circuit Failure Power Liftgate Module Go To Pinpoint Test B . B2699 Left Pinch Strip Open or Short to Battery Power Liftgate Module Go To Pinpoint Test B . B2700 Right Pinch Strip Open or Short to Battery Power Liftgate Module Go To Pinpoint Test B . B2701 Left Pinch Strip Stuck Active Power Liftgate Module Go To Pinpoint Test B . B2702 Right Pinch Strip Stuck Active Power Liftgate Module Go To Pinpoint Test B . B2703 Open/Close Switch Stuck Active Power Liftgate Module Go To Pinpoint Test B . B2704 Optical Sensor Power Short to Ground Power Liftgate Module Go To Pinpoint Test B . B2705 Optical Sensor 1 Input Not Active During Powered Gate Movement Power Liftgate Module Go To Pinpoint Test B . B2706 Optical Sensor 2 Input Not Active During Powered Gate Movement Power Liftgate Module Go To Pinpoint Test B . B2709 Gate Open Output Short to Battery Power Liftgate Module Go To Pinpoint Test B . B2710 Gate Close Output Short to Battery Power Liftgate Module Go To Pinpoint Test B . B2711 Gate Open Output Short to Ground or Open Power Liftgate Module Go To Pinpoint Test B . B2712 Gate Close Output Short to Ground or Open Power Liftgate Module Go To Pinpoint Test B . B2713 Unlatch Output Short to Ground or Open Power Liftgate Module Go To Pinpoint Test B . B2714 Uncinch Output Short to Ground or Open Power Liftgate Module Go To Pinpoint Test B . B2715 Cinch Output Short to Ground or Open Power Liftgate Module Go To Pinpoint Test B . B2718 Gate Ajar Output Short to Battery Power Liftgate Module Go To Pinpoint Test B . B2721 Gate Ajar Output Short to Ground or Open Power Liftgate Module Go To Pinpoint Test B . B2722 Open/Close Switch Active During Self-Test Power Liftgate Module Go To Pinpoint Test B . B2723 Glass Position Switch Active During Self-Test Power Liftgate Module Go To Pinpoint Test B . B2724 Forkbolt Switch Invalid During Self-Test Power Liftgate Module Go To Pinpoint Test B . B2725 Detent Switch Invalid During Self-Test Power Liftgate Module Go To Pinpoint Test B . B2726 Home Switch Invalid During Self-Test Power Liftgate Module Go To Pinpoint Test B . B2819 Gate Motor Circuit Short to Battery Power Liftgate Module Go To Pinpoint Test B . B2820 Gate Motor Circuit Short to Ground or Open Power Liftgate Module Go To Pinpoint Test B . B2821 Cincher Motor/Unlatch Actuator Short to Ground or Open Power Liftgate Module Go To Pinpoint Test B . B2822 Cincher Motor/Unlatch Actuator Short to Battery Power Liftgate Module Go To Pinpoint Test B . B2825 Movement Ceased Due to Excess Speed Deviation Power Liftgate Module Go To Pinpoint Test B . B2903 Chime Output Circuit Short to Battery Power Liftgate Module/ Liftgate Chime Module Go To Pinpoint Test C . C1935 Chime Circuit Failure Power Liftgate Module/ Liftgate Chime Module Go To Pinpoint Test C . U1950 UBP Communication BUS Fault UBP Communi- cation REFER to Section 418-00 . U2338 Invalid ACM Message Data Power Liftgate Module REFER to Section 418-00 . U2242 Invalid 4WAS Message Data 4WAS Module REFER to Section 308-07A . U2403 Invalid CSM Message Data Vehicle Security Module REFER to Section 418-00 . U2406 Invalid IC Message Data Instrument Cluster Module REFER to Section 413-01 . U2469 Power Liftgate Disabled By Customer Interface Instrument Cluster Module Turn power liftgate on at message center. U2470 Unexpected Keyfob/Keypad Button Press Power Liftgate Module Go To Pinpoint Test A . U2471 Unexpected PRNDL State Power Liftgate Module REFER to Section 419-10 . U2472 Unexpected IGN State Power Liftgate Module REFER to Section 418-00 . U2473 Unexpected Vehicle Speed Instrument Cluster Module/ Powertrain Control Module REFER to Section 413-01 . U2528 PRNDL Data Mismatch Power Liftgate Module/ Instrument Cluster Module Go To Pinpoint Test D .