Airbags

B00C9 — Passenger Seat Occupant Position Sensor C Fault

Severity: medium Safe to drive

What B00C9 means

The airbag (SRS) control module detected a fault in the circuit of sensor C, which helps determine the position or presence of the front passenger. The system uses this data to decide whether to deploy the passenger airbag and how forcefully. With a fault, the data can't be trusted and the system may behave incorrectly.

Symptoms

  • SRS or passenger airbag warning light on or flashing
  • Occupant detection fault message
  • Passenger airbag status shows off or incorrect
  • No change in engine or transmission behavior

Possible causes

  1. Failed occupant position sensor C in the seat
  2. Damaged wiring harness under the seat or a poor connector contact
  3. Corroded or loose connector from seat movement
  4. SRS module or module communication fault
  5. Low system voltage or a weak battery

How to diagnose

  1. Scan for codes with a tool that reads SRS and note any related codes
  2. Inspect the harness and connectors under the passenger seat for wear, pinching and corrosion
  3. Check for objects or moisture under and in the seat
  4. Test battery voltage and ground condition
  5. Watch live sensor data with the seat empty and occupied
  6. Test circuit continuity and resistance per the manufacturer's wiring diagram
  7. Clear the code and see if it returns

Common fixes

  • Replace occupant position sensor C
  • Repair the wiring or replace the damaged connector
  • Clean and secure the connector contacts
  • Replace or reprogram the SRS module if confirmed faulty

Questions and answers

What does B00C9 mean?

It indicates a fault in the circuit of passenger seat occupant position sensor C. The SRS module isn't getting reliable data about the front passenger.

Can I drive with B00C9?

Yes, the car drives normally, but passenger protection may not work as intended. Get it fixed soon.

Will clearing the code fix it?

Only if the cause was temporary, like low battery voltage. If the sensor or wiring is faulty, the code will return.

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.