Airbags

B00C4 — Passenger Seat Occupant Classification Sensor E Fault

Severity: medium Drive with care, to a shop

What B00C4 means

B00C4 means the airbag control module found a fault in occupant classification sensor E in the passenger seat. The occupant classification system (OCS) tells whether the seat is empty, holds an adult, a child or a child seat, and the airbag logic uses that to decide if the front passenger airbag should deploy. With this fault, the module can't trust the sensor's data.

Symptoms

  • Airbag (SRS) warning light is on
  • Passenger airbag status indicator flickers or behaves oddly
  • Passenger airbag shows OFF with an adult in the seat
  • Airbag stays ON with an empty seat or a child seat

Possible causes

  1. Failed occupant classification sensor E
  2. Damaged wiring harness to the sensor under the seat
  3. Corroded or loose connector pins
  4. Objects, cargo or seat cover interfering, or a mechanically distorted seat
  5. OCS calibration lost after seat repair or replacement
  6. Faulty airbag control module (rare)

How to diagnose

  1. Read all SRS codes with a scan tool that supports airbags and note the freeze frame
  2. Check the seat for objects, aftermarket covers, heaters or cushions that could affect the sensor
  3. Inspect the harness and connector under the passenger seat for chafing, pinching, corrosion and a secure latch
  4. Disconnect the battery and wait the manufacturer's specified time before unplugging any SRS connector
  5. Test circuit continuity and resistance per the factory wiring diagram
  6. View OCS live data with the seat empty and with a known weight on it
  7. Clear the code and confirm it doesn't return

Common fixes

  • Replace occupant classification sensor E
  • Repair or replace the damaged harness or connector
  • Clean and restore connector terminals
  • Recalibrate or zero the OCS with a scan tool per the manufacturer's procedure
  • Replace the airbag module if it is confirmed faulty

Questions and answers

What does B00C4 mean?

It indicates a fault in occupant classification sensor E. The airbag module can't reliably tell who or what is on the front passenger seat.

Is it safe to drive with B00C4?

You can drive, but the passenger airbag may not respond correctly in a crash. Don't carry children in the front seat and get it diagnosed promptly.

Can I just clear the B00C4 code?

Clearing may work briefly if the cause was a one-time glitch. If the fault is real, the SRS light will return, so the sensor and wiring need to be checked.

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.