What does it mean?
B1216 is a Body (airbags, seat belts, body electronics) fault code. It indicates: Rear Center Right Sensor Fault .
Symptoms
- Parking aid fault message or warning lamp when reverse is selected
- Continuous tone as soon as reverse gear is engaged, instead of distance beeps
- Rear parking aid completely switched off, so obstacles behind the vehicle are not detected
- Blind spot in the centre right of the rear bumper while the corner sensors still respond
- False warnings with nothing behind the vehicle, especially in cold or wet weather
- Reversing camera guidance overlay or automatic parking unavailable
Likely causes
- Sensor internally failed or filled with water after years of spray from the rear wheels
- Sensor face covered with road film, ice, snow, wax or paint from bumper refinishing
- Sensor knocked out of its retaining ring or misaligned by a reversing bump
- Rear bumper harness chafed, crushed or damaged during towbar or trailer socket installation
- Corroded connector from road salt, high-pressure washing or a failed seal
- Poor supply, bad ground or a blown fuse at the parking aid module
- Module input fault or a break in the sensor communication line
How to fix it
- Clean the sensor face and inspect for paint build-up, cracks and correct seating in its ring
- Read individual rear sensor distances in live data while an assistant moves an object towards each sensor
- With reverse selected, listen or feel for each sensor ticking to find the silent one
- Inspect the rear bumper harness for damage near the towbar, trailer socket and exhaust heat
- Check the connector for corrosion and confirm supply voltage and ground at the module
- Swap the suspect sensor with a known good one from another rear position and see whether the fault follows
- Replace the sensor or repair the harness, clear the code and verify all rear sensors report plausible distances