Circuit/System Testing

Interior Liftgate Control Switch Inoperative

1. Ignition OFF, disconnect the harness connector at the interior liftgate control switch.
2. Test for less than 1 ohm between the ground circuit terminal C and ground.
   • If greater than the specified range, test the ground circuit for an open/high resistance.
3. Ignition ON, verify the scan tool LGM Disable Switch parameter is Inactive.
   • If not the specified value, test the signal circuit terminal A for a short to ground. If the circuit tests normal, replace the LGM.
4. Verify the scan tool LGM Front Control Switch parameter is Inactive.
   • If not the specified value, test the signal circuit terminal D for a short to ground. If the circuit tests normal, replace the LGM.
5. Install a 3A fused jumper wire between the signal circuit terminal A and ground. Verify the scan tool LGM Disable Switch parameter is Active.
   • If not the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the LGM.
6. Install a 3A fused jumper wire between the signal circuit terminal D and ground. Verify the scan tool LGM Front Control Switch parameter is Active.
   • If not the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the LGM.
7. If all circuits test normal, test or replace the interior liftgate control switch.

Liftgate Handle Switch Inoperative

1. Ignition OFF, disconnect the harness connectors at the liftgate handle switch and liftgate close switch.
2. Test for less than 20 ohms between the low reference circuit listed below and ground:
   • Liftgate handle switch low reference terminal B
   • Liftgate close switch low reference terminal A
   • If greater than the specified range, test the low reference circuit for a short to voltage or an open/high resistance.
3. Ignition ON, verify the scan tool Liftgate Handle Sw. Status parameter is Inactive.
   • If not the specified value, test the signal circuit terminal D for a short to ground. If the circuit tests normal, replace the LGM.
4. Ignition OFF, connect the harness connector at the liftgate close switch.
5. Ignition ON, observe the scan tool Liftgate Handle Sw. Status parameter while pressing and releasing the liftgate close switch, the parameter should change between Active and Inactive.
   • If the value does not change, test or replace the liftgate close switch.
6. If all circuits test normal, test or replace the liftgate handle switch.

Power Liftgate Inoperative

1. Ignition OFF, disconnect the harness connector at the liftgate latch assembly.
2. Ignition ON, verify the scan tool LGM Latch Pawl Sw. parameter is Inactive.
   • If not the specified value, test the signal circuit terminal 5 for a short to ground. If the circuit tests normal, replace the LGM
3. Verify the scan tool LGM Latch Sector Sw. parameter is Inactive.
   • If not the specified value, test the signal circuit terminal 4 for a short to ground. If the circuit tests normal, replace the LGM.
4. If all circuits test normal, replace the liftgate latch assembly.

Liftgate Closes and Reopens

IMPORTANT:

Check the alignment of the liftgate striker, if the liftgate striker is adjusted too far inboard it could allow the LGM to detect an excess motor current condition and reverse the motor.

1. Ignition OFF, disconnect the X1 harness connector at the LGM.
2. Test for infinite resistance between the signal circuit terminal 8 and ground.
   • If less than the specified value, test the signal circuit for a short to ground.
3. Test for 15k-25k ohms between the signal circuit terminal 8 and the low reference circuit terminal 16.
   • If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the left or right liftgate object sensor.
   • If not within the specified range, test the signal circuit between the left and right liftgate object sensors and the low reference circuit for an open/high resistance. If the circuits test normal, test or replace the left or right liftgate object sensor.
4. If all circuits test normal, replace the LGM.