9-7X L6-4.2L (2008)
3. Command the rear window defogger ON and OFF with a scan tool. The rear window defogger should turn ON and OFF when changing between
the commanded states.
Circuit/System Testing
1. Ignition OFF, disconnect the X1 harness connector at the LGM
2. Ignition ON, verify a test lamp illuminates between the B+ circuit terminal A and ground.
‹› If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit tests normal and the LGM
#2 fuse is open, replace the LGM.
3. Ignition OFF, reconnect the harness connector at the LGM and disconnect the harness connector at the rear window defogger grid.
4. Test for less than 1.0 ohm between the ground circuit terminal A and ground.
‹› If greater than the specified range, test the ground circuit for an open/high resistance.
5. Connect a test lamp between the control circuit terminal A and ground.
6. Ignition ON, command the rear window defogger ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between
the commanded states.
‹› If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the LGM.
‹› If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the
LGM.
7. If all circuits test normal, test or replace the rear window defogger.
Component Testing
1. Ignition ON, turn on the rear window defogger.
2. Verify that a test lamp illuminates between each rear window defogger grid line and ground. The test lamp should be off when testing at the
ground side of the grid and get brighter as the test lamp moves closer to the voltage supply side of the grid. The test lamp should be dim when
testing each grid line in the middle.
‹› If the test lamp remains bright at the middle of the grid line, test for an open between the test point and the ground side of the grid.
‹› If the test lamp remains off at the middle of the grid line, test for an open between the test point and the voltage supply side of the grid.
Repair Instructions
Perform the Diagnostic Repair Verification (See: Powertrain Management/Computers and Control Systems/Testing and Inspection/Diagnostic Trouble
Code Tests and Associated Procedures/Verification Tests and Procedures) after completing the diagnostic procedure.
*
Liftgate Window Replacement (See: Windows/Window Glass/Liftgate Window Glass/Service and Repair)
*
Control Module References (See: Testing and Inspection/Programming and Relearning/Control Module References) for HVAC control module
and LGM replacement, setup, and programming
