Passenger Seat Occupant Detection Circuit Short To Battery
The passenger seat occupant detection sensor is sending a constant high voltage signal to the ECU, like a stuck switch that won't turn off. This prevents the airbag system from properly detecting whether someone is sitting in the passenger seat.
The ECU monitors the occupant detection circuit voltage to determine seat occupancy status. It expects a variable voltage signal that changes based on weight/pressure; a constant high voltage indicates a short to the battery, preventing normal signal interpretation.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| Occupant Detection Voltage | 0.5-4.5V (variable with occupancy) | Continuously above 11V (shorted to battery) |
| Signal Stability | Dynamic response to seat pressure changes | Static high voltage with no variation |
Code B2587 is a low-severity fault. Your vehicle is generally safe to drive to a workshop for diagnosis. However, do not ignore it indefinitely — low-severity codes often indicate developing problems that become expensive if neglected. Book a diagnostic appointment within 2–4 weeks. If you notice any additional symptoms (rough running, power loss, unusual smells), treat it as higher priority.
Once the fault is repaired, B2587 can be cleared using any OBD-II scanner. Connect the scanner, navigate to "Clear Codes" or "Erase DTCs," and confirm. The check engine light turns off immediately.
The code will return if the root cause was not actually fixed. The ECM re-detects the fault within 1–3 drive cycles and sets the code again.