What does it mean?
Because this is a B-code, this DTC (diagnostic trouble code) refers to a fault in one of the body control systems, such as climate control, airbags, power windows, or lighting. Because it is a B1-code, each manufacturer has its own definition for this DTC, and a few automakers reserve this DTC for the airbag system. Here are a few common definitions: Toyota – Airbag System – Occupancy Sensor System Error (Front Passenger Seat w/o Passenger Air Bag Deactivation (PAD) Switch) Mercedes-Benz – Airbag System – Right Front Side Airbag Ignition Squib Short Circuit Ford / Mazda – Airbag System – Passenger Air Bag Deactivation (PAD) Switch Fault General Motors – Driver Head Restraint Up Switch Circuit Range / Performance
Symptoms
- Air bag warning lamp on and the passenger air bag status indicator shows the wrong state
- Passenger air bag stays disabled with a normal adult in the seat, or stays enabled with the seat empty
- Status indicator flickers when the occupant shifts position
- Seat belt reminder chime behaves incorrectly for the passenger seat
- Side or front passenger restraints are disabled until the fault is repaired
Likely causes
- Faulty occupant classification sensor mat or bladder in the front passenger seat cushion
- Passenger air bag deactivation switch worn, sticking between positions or internally open
- Under seat connector unplugged, dirty or corroded after floor cleaning or water ingress
- Harness pinched or stretched by seat travel on the rails
- Objects wedged under the cushion, a heavy aftermarket seat cover or a child seat base loading the sensor incorrectly
- Short circuit in a side air bag inflator (squib) branch on systems that assign this code to that circuit
- Occupant classification system never zeroed or calibrated after seat, cushion or module replacement
How to fix it
- Observe air bag safety rules: ignition off, battery disconnected and the specified stand time completed before disturbing any restraint connector
- Read all restraint codes and the freeze frame, then check the passenger air bag status indicator behaviour with the seat empty and with weight applied
- Empty the seat, remove anything stored underneath and take off heavy aftermarket covers, then recheck the classification data on the scan tool
- Inspect the under seat connectors: unlatch, look for pin fretting, corrosion and moisture, reseat fully and check that the yellow connector locks are engaged
- Slide the seat through its full travel while watching live data to expose a stretched or pinched harness
- Measure sensor and squib circuit resistance against the specification with an approved meter instead of guessing
- Replace the sensor mat, deactivation switch or seat cushion assembly as indicated, and treat the control module as the last step