Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Possible Causes
Diagnostic Trouble Code (DTC) B1781 could be caused by an open, short, short to ground or short to battery in occupant classification right front sensor circuit, occupant classification right front sensor malfunction, occupant classification Electronic Control Unit (ECU) malfunction.
If wire harness inspection is difficult to perform, remove right front seat mounting bolts to access area under seat cushion. Hold seat in such a way so it will not fall. Holding seat for prolonged periods of time may cause seat rail deformation. Hold seat only when necessary.
NO RELATED
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.