B1322

Step 1: Visually inspect the wiring harness in the driver door jamb area where it flexes during door operation. Look for pinched, chafed, or damaged insulation that could be causing a short to ground. Check rubber conduit boots for tears or deterioration.

Step 2: Disconnect the driver door ajar switch connector and measure resistance between the switch signal wire and vehicle ground using a digital multimeter. Should read infinite resistance (open circuit). If resistance is low (under 5 ohms), trace wiring from switch to BCM for short to ground.

Step 3: With switch disconnected, check the switch itself by measuring resistance across its terminals while manually actuating the plunger. Switch should show continuity when pressed (door open) and open circuit when released (door closed). Replace switch if operation is incorrect or if it shows continuity to ground.

Step 4: Inspect all connectors in the circuit for corrosion, pushed-back pins, or moisture intrusion. Pay special attention to the door switch connector and BCM connector. Clean or repair as necessary.

Step 5: If all wiring and switch test good, check BCM ground connections for integrity. Measure voltage drop between BCM ground terminal and battery negative while circuit is active (should be less than 0.1V).

Step 6: Clear codes, reconnect all components, cycle the driver door multiple times, and verify the DTC does not return. Confirm interior lights, door ajar warning, and security system respond correctly to door operation.