Diagnostic Routine C

Diagnostic Routine C

Diagnostic Overview

The Power Liftgate Stops in Secondary Latch Position

Normal Operations and Fault Conditions

When the power liftgate moves in the close direction, the LTM (Liftgate/Trunk Module) monitors the detent switch, secondary forkbolt switch and the primary forkbolt switch. When the combination of signals is received indicating the liftgate has reached the secondary latch position, the LTM (Liftgate/Trunk Module) supplies voltage and ground to the unlatch/cinching motor to cinch the liftgate to the primary latch position. The unlatch/cinching motor rotates the latch mechanism, pulling the liftgate into primary latch position.

The LTM (Liftgate/Trunk Module) halts the cinch operation if it determines that it cannot achieve the primary latch position. This could be due to a failure with the latch, switches, or wiring. It can also be caused by a binding liftgate that does not close correctly.

DTC Fault Trigger Conditions






Visual Inspection and Diagnostic Pre-checks

- Liftgate alignment

- Liftgate striker alignment

- Mechanical binding

Pinpoint Test

1. CHECK THE MANUAL OPERATION OF THE LIFTGATE

1. Turn the power liftgate off (disable) from the message center.

2. While manually opening and closing the liftgate, check the liftgate for:

- liftgate/wedge alignment
- strut operation (struts should push liftgate open when beyond half open)
- power liftgate motor (should move freely while manually opening and closing liftgate and be securely mounted to the liftgate and bracket)
- power liftgate latch (should latch completely)

Does the liftgate open and close correctly?








2. CHECK THE LIFTGATE LATCH AND STRIKER ALIGNMENT

1. NOTE: Make sure to inspect the underside of the striker bridge for witness marks.
Inspect the striker and latch for correct alignment.

Is the latch and striker aligned correctly?








3. CHECK THE DETENT AND FORKBOLT SWITCH PIDs (Parameter Identifications)

1. Using the scan tool, view LTM (Liftgate/Trunk Module) PIDs (Parameter Identifications).

2. Operate the liftgate manually while monitoring the LTM (Liftgate/Trunk Module) PIDs (Parameter Identifications):

- Detent Switch Status (DETENTSW)
- Forkbolt Switch Status (FORKBLT_S)
- Forkbolt Secondary Switch (FKSWSEC)

3. NOTE: The liftgate is in the primary position when the liftgate is in the full closed position. The liftgate is in the unlatch position when the liftgate is open and completely out of the striker.

NOTE: If detent switch is active in the fully unlatched position, manually attempt to rotate the forkbolt towards the latched position.
Begin with the liftgate in the open position, then slowly close the liftgate into each of the latch positions specified by the table below.





Do the switch states agree with the table?








4. CHECK FOR CORRECT LTM (Liftgate/Trunk Module) OPERATION

1. Ignition OFF.

2. Disconnect and inspect all LTM (Liftgate/Trunk Module) connectors.

3. Repair:

- corrosion (install new connector or terminals - clean module pins)
- damaged or bent pins - install new terminals/pins
- pushed-out pins - install new pins as necessary

4. Reconnect all the LTM (Liftgate/Trunk Module) connectors. Make sure they seat and latch correctly.

5. Operate the system and determine if the concern is still present.

Is the concern still present?