B2337

Step 1: Perform visual inspection of mirror switch assembly and connector for obvious damage, corrosion, bent pins, or water intrusion. Check connector locking mechanism is secure and pins are properly seated.

Step 2: Using a digital multimeter, check for battery voltage (typically 12V) at the switch power supply wire with ignition on. Verify ground circuit continuity to chassis ground (should be less than 0.5 ohms resistance).

Step 3: Disconnect mirror switch connector and measure resistance across switch terminals while operating the switch through all positions. Compare readings to manufacturer specifications (typically should show varying resistance values, not infinite/open circuit).

Step 4: Inspect door harness flex area between door jamb and door body for broken wires by gently flexing the harness while monitoring circuit continuity with multimeter. Look for intermittent open circuits.

Step 5: If all wiring and switch test good, verify BCM connector terminals for corrosion and proper seating. Check BCM ground connections are clean and tight with less than 0.5 ohms resistance to chassis ground.

Step 6: After repairs, clear codes, cycle mirror switch through all positions multiple times, and verify code does not return. Perform several door open/close cycles to confirm repair holds.