Door Switch: Testing and Inspection

The following diagnosis and testing is only for the chime functions. For interior lamp diagnosis, refer to the appropriate wiring information. The driver door ajar switch is hard wired to the Driver Door Module (DDM). The DDM communicates the switch status to the other modules in the vehicle on the Programmable Communications Interface (PCI) data bus network. The following test will diagnose a faulty driver door ajar switch and circuits. For complete circuit diagrams, refer to the appropriate wiring information.

WARNING: ON VEHICLES EQUIPPED WITH AIRBAGS, REFER TO ELECTRICAL, RESTRAINTS BEFORE ATTEMPTING ANY STEERING WHEEL, STEERING COLUMN, OR INSTRUMENT PANEL COMPONENT DIAGNOSIS OR SERVICE. FAILURE TO TAKE THE PROPER PRECAUTIONS COULD RESULT IN ACCIDENTAL AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL INJURY.

1. Check that the interior lighting switch on the control stalk of the left multi-function switch is not in the dome lamp disable position. Open the driver side front door and note whether the interior lamps light. They should light. If OK, refer to Key-In Ignition Switch in the Diagnosis and Testing section of this group for further diagnosis of the chime warning system. If not OK, go to Step 2.
2. Disconnect and isolate the battery negative cable. Remove the trim panel from the driver front door and disconnect the 4-way door wire harness connector from the front door latch connector. Check for continuity between the ground circuit of the 4-way door wire harness connector and a good ground. There should be continuity. If OK, go to Step 3. If not OK, repair the ground circuit.
3. Disconnect the door wire harness connector from the Driver Door Module (DDM) connector. Check for continuity between the driver door ajar switch sense circuit of the door wire harness connector for the DDM and a good ground. There should be no continuity. If OK, go to Step 4. If not OK, repair the shorted driver door ajar switch sense circuit.
4. Check for continuity between the driver door ajar switch sense circuit of the door wire harness connector for the DDM and the 4-way door wire harness connector for the front door latch. There should be continuity. If OK, go to Step 5. If not OK, repair the open driver door ajar switch sense circuit.
5. Check for continuity between the ground circuit terminal and the driver door ajar switch sense circuit terminal of the front door latch connector. There should be continuity with the driver side front door open, and no continuity with the door closed. If OK, use a DRB III scan tool and the proper Diagnostic Procedures to test the operation of the PCI data bus and the DDM. If not OK, replace the faulty driver side front door latch unit.