Decklid Release Circuit Failure
The trunk/decklid release mechanism isn't communicating properly with the vehicle's computer, similar to a remote control that won't talk to your TV. The electrical circuit controlling the trunk release has either an open connection, short, or the motor/solenoid has failed.
The ECU monitors voltage and current flow through the decklid solenoid circuit when the release button is pressed. It expects a specific voltage drop across the solenoid and detects either an open circuit (no current flow) or short circuit (excessive current). If the measured values fall outside normal operating thresholds, the fault code is set.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| Solenoid Voltage | 12V applied when button pressed, ~0.5-2A current draw | 0V or <5V, or >5A current (short) |
| Circuit Resistance | 6-12 ohms (nominal solenoid coil) | <1 ohm (short) or >50 ohms (open/corrosion) |
Code B1551 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, B1551 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.