What does it mean?
B1451 is a Body (airbags, seat belts, body electronics) fault code. It indicates: SIS (Side Impact Sensor) Rear-Driver Circuit Short to Ground .
Symptoms
- Airbag/SRS warning lamp on and staying on
- Side and curtain airbag protection on the driver side is inhibited
- Rear seat belt pretensioner on that side may also be disabled
- Fault often becomes permanent after heavy rain, a car wash or a load being dragged over the rear sill
- Code returns immediately after clearing while the short is still present
Likely causes
- Sensor harness chafed against a body seam, sill edge or seat rail in the rear of the cabin
- Water intrusion at the sensor connector from a leaking door seal, a blocked drain or a wet carpet
- Insulation damaged during audio, alarm or trim installation work in the rear quarter
- Internal short inside the side impact sensor
- Corroded connector pins letting the circuit leak to the sensor mounting bracket
- Ground short inside the airbag control unit connector or its input stage
How to fix it
- Retrieve all SRS codes and note whether other side impact sensor faults are stored at the same time
- Power the system down: ignition off, battery disconnected, prescribed wait observed
- Unplug the rear driver-side impact sensor and measure the resistance from each signal wire to a clean chassis ground; a low reading with the sensor unplugged confirms a harness short
- Peel back the sill and rear quarter trim and follow the harness for chafe marks, staples, screws or crushed sections
- Check the sensor connector and the carpet under it for water, and trace the leak that let it in
- If the harness is clean, back-probe the circuit at the airbag control unit connector and repeat the measurement to separate the harness from the module
- Repair the damaged wire using the approved method for SRS wiring, dry and protect the connector, then replace the sensor only if the circuit tests good
- Clear the codes and confirm the lamp completes a normal bulb check and goes out