Airbags

B00B9 — Driver Seat Occupant Position Sensor 'C' Fault

Severity: medium Safe to drive

What B00B9 means

B00B9 means the airbag (SRS) control module detected a problem in sensor 'C' or its circuit, which reports the driver's position in the seat. The module uses this data to decide how airbags and pretensioners should deploy. When the signal is unreliable, it turns on the airbag light and may limit some restraint functions.

Symptoms

  • Airbag/SRS warning light on or flashing
  • Occupant detection or restraint system warning message
  • Fault that comes and goes as the seat moves
  • Driver airbag possibly disabled by the system

Possible causes

  1. Failed driver seat occupant position sensor 'C'
  2. Open or shorted wiring under the driver seat
  3. Corroded, loose or damaged sensor connector
  4. Wiring damaged by seat adjustment, cleaning or aftermarket seat covers
  5. Faulty SRS control module (uncommon)

How to diagnose

  1. Scan all modules with an SRS-capable tool and note freeze-frame data
  2. Inspect the wiring and connectors under the driver seat for damage, corrosion and a secure fit
  3. Check for moisture, objects or seat covers interfering with the sensor
  4. Test circuit resistance and shorts to ground or power per the manufacturer's wiring diagram
  5. Move the seat through its range while watching sensor data on the scan tool
  6. Check battery voltage and the SRS module ground
  7. Clear the code and see whether it returns

Common fixes

  • Replace occupant position sensor 'C'
  • Repair or replace the damaged wiring section
  • Clean, repair or replace the connector and secure it
  • Replace or reprogram the SRS module if confirmed faulty

Questions and answers

Can I drive with B00B9?

Yes, the car will still run normally. But the driver's airbag protection may not work as intended, so get it diagnosed promptly.

Why is my airbag light on with this code?

The SRS module is not getting reliable position data from the driver seat sensor, so it warns you with the light. It usually stays on until the fault is fixed.

Can I fix B00B9 myself?

You can inspect the connectors under the seat, but SRS work requires disconnecting the battery and care. Sensor replacement is best left to a qualified technician.

This is general information about the code. The meaning can differ between makes and models: a scan tool and the repair manual for your car will show the exact cause.