B2263

Step 1: Perform a visual inspection of both mirror assemblies and their connectors at the door. Check for physical damage, water intrusion, corrosion on pins, or loose connections. Wiggle connectors while monitoring live data for signal dropouts.

Step 2: Using a digital multimeter, backprobe the mirror position sensor signal circuit at the mirror connector (typically 5V reference, signal, and ground). Verify 5V reference voltage is present and ground circuit has less than 0.1V resistance to chassis ground.

Step 3: With ignition on, manually move the affected mirror through its full range of motion while monitoring the position sensor signal voltage with a multimeter or scan tool live data. Signal should sweep smoothly between approximately 0.5V and 4.5V without dropouts or erratic readings.

Step 4: Inspect the door harness wiring in the hinge area by flexing the door open and closed while monitoring the sensor signal. Look for intermittent signal loss indicating broken wires inside the insulation.

Step 5: If wiring and voltage supply are correct but sensor signal is erratic or stuck, replace the affected mirror assembly. If both mirrors show issues simultaneously, suspect BCM fault or power supply issue.

Step 6: After repair, clear codes, perform mirror calibration procedure per manufacturer specifications (typically moving mirrors through full range), and verify proper operation of memory and auto-dimming functions.