B00B4

What it means

B00B4 is defined as a fault with Driver Seat Occupant Classification Sensor E, part of the system that detects whether the driver seat is occupied and by whom. The airbag control unit sets it when the signal from that sensor is missing, out of range, implausible or the circuit is faulty. The exact meaning of sensor E and the exact fault type depend on the vehicle and the manufacturer's documentation.

Symptoms

• Airbag or SRS warning light on
• Passenger or driver airbag status indicator behaving oddly (model dependent)
• Seat occupancy or seat belt reminder warning that is wrong or intermittent
• Airbag may be disabled or may not respond correctly to the seat occupant
• Fault returns after being cleared, especially after the seat is used or moved

Possible causes

• Damaged or poorly seated wiring or connector under the driver seat, often from seat movement or items stored underneathlikely
• Faulty occupant classification sensor or sensor mat in the driver seatlikely
• Corroded or loose terminals in the seat connector, or a connector that was not refitted fully after seat workpossible
• Seat mounting or structure disturbed, causing incorrect load readings on weight-based sensors (system type depends on the model)possible
• Low or unstable supply voltage or poor earth affecting the SRS circuitpossible
• Fault within the airbag control unit or occupant classification modulerare

How to diagnose

1. Record the full code list and freeze frame data, and note whether B00B4 is current, stored or intermittent, and whether other SRS or seat codes are present.
2. Ask about recent seat removal, upholstery work, seat cover fitting, collision damage or liquid spills, as these commonly trigger seat sensor faults.
3. Check battery condition and charging voltage, as low voltage can cause false SRS faults.
4. Visually inspect the driver seat wiring, clips and connector for pinching, chafing, damage, water ingress and corrosion, following the manufacturer's SRS safety procedure (isolate the battery and wait the specified time first).
5. Check the seat is correctly fitted and bolted, with nothing trapped or loading the seat sensor.
6. Using the manufacturer's wiring diagram, test circuit continuity, resistance, and short to earth or supply, using only the approved method for SRS circuits and never a test lamp.
7. Check live data for the sensor, if available, with the seat empty and occupied, and compare with the specification for that model.
8. Clear the code after repair, then recheck with the seat empty, occupied and moved through its range to confirm it stays away.

How to fix

• Repair or replace damaged wiring, and refit the connector securely with the locking mechanism fully engaged.
• Clean or replace corroded connector terminals, and fix any source of water ingress.
• Replace the faulty driver seat occupant classification sensor or mat, and complete any setup or zeroing procedure the manufacturer requires.
• Correct the seat fitting or mounting if it is affecting the readings.
• Repair battery, supply or earth faults found during testing.
• Replace the airbag or occupant classification control unit only after all other causes are ruled out and the manufacturer's procedure confirms it.

Can I keep driving?

Nearby codes

• B00B3GenericDriver Seat Occupant Classification Sensor D
• B00B5GenericDriver Seat Track Position Restraints Sensor