What does it mean?
B1911 is a Body (airbags, seat belts, body electronics) fault code. It indicates: Outside Mirror - Left Vertical Motor or Sensor Error .
Symptoms
- Left mirror does not tilt up or down while sideways movement still works
- Motor noise with no movement of the glass
- Memory recall leaves the mirror at the wrong vertical angle
- Reverse tilt function does not operate on the left side
- Adjustment works intermittently and may recover after the door is slammed
Likely causes
- Vertical mirror motor seized or worn out from repeated use
- Stripped gears or a broken pivot in the mirror actuator after the glass was pushed by hand or by a car wash brush
- Worn vertical position potentiometer on memory mirror systems
- Broken conductor in the door jamb boot harness or inside the door loom
- Water and corrosion in the mirror connector, common where the door membrane is damaged
- Mirror glass frozen or blocked by ice, overloading the motor
- Door or memory module output driver failure
How to fix it
- Test both axes on both mirrors and record which movements fail, since a single axis failure points to the actuator rather than the supply
- Check for ice, dirt or trim fouling holding the glass before removing parts
- Watch mirror position live data while adjusting to see whether the vertical channel responds at all
- Measure the command voltage at the mirror connector while the switch is operated in both directions
- Flex the door jamb boot harness while monitoring the circuit to reveal a broken wire
- Repair the harness or connector first, then replace the mirror actuator or glass carrier if the motor or sensor is faulty
- Replace the controlling module only when wiring and actuator have both tested good