What does it mean?
B1782 is a Body (airbags, seat belts, body electronics) fault code. It indicates: Occupant Classification Sensor Rear LH Circuit Malfunction .
Symptoms
- Airbag warning lamp on and occupant classification disabled
- Passenger airbag status indicator behaving incorrectly, on with an empty seat or off with an adult
- One corner of the live weight data reading zero or wildly different from the others
- System refuses to complete its calibration routine
- Fault appears after seat work, luggage being loaded onto the seat, or a child seat being fitted
Likely causes
- Connector at the rear left of the seat base corroded, loose or not relatched
- Sensor lead trapped between the seat frame and the rail, or crushed by an object under the seat
- Water from the carpet or a leaking seal reaching the rear connector
- Load cell damaged by a heavy item dropped on the rear of the cushion or by kneeling on the seat back
- Rear mounting bolts loose, or the seat rail distorted so the rear corner is preloaded
- Cargo or a child seat base wedged against the rear of the seat, adding a false load
- Occupant classification module fault
How to fix it
- Read the codes and compare all four corner readings with the seat completely empty
- Take everything off and out from under the seat, including covers and stored items
- Inspect the rear left sensor connector for corrosion, moisture, spread or backed-out terminals
- Wiggle the lead while sliding the seat through its full range and watch for the value to drop out
- Check the rear mounting bolts, the seat rail alignment and that nothing touches the frame
- Perform the specified zero or calibration routine and see whether the readings return to normal
- Replace the sensor or seat frame assembly as directed, then recalibrate and confirm with a known load