B1632

Step 1: Perform visual inspection of the driver side mirror wiring harness, paying close attention to the rubber boot section between door and body where wiring flexes. Look for chafed, broken, or disconnected wires and inspect all connectors for corrosion, bent pins, or moisture intrusion

Step 2: Using a digital multimeter, check for continuity between the BCM connector (mirror control circuit pins) and the driver mirror connector with ignition off. Consult vehicle-specific wiring diagrams to identify correct pin assignments. Expect less than 5 ohms resistance on intact circuits

Step 3: Disconnect the driver side mirror connector and measure resistance across the mirror motor terminals. Compare readings to manufacturer specifications (typically 3-15 ohms for functional motors). Infinite resistance indicates open motor windings

Step 4: Apply direct 12V power to the mirror motor terminals using a power probe or jumper wires to verify mechanical operation of all mirror adjustment directions. If mirror operates normally, fault is in wiring or BCM

Step 5: Check for battery voltage and ground at the mirror connector with ignition on and mirror switch activated in each direction. Lack of voltage or ground indicates BCM or wiring fault upstream

Step 6: Clear the code, operate the mirror through all adjustment positions, and rescan for code return. If code does not return and mirror functions normally, repair was successful. Verify proper operation of mirror fold and heat functions if equipped