Air Bag Crash Sensor #2 Feed/Return Circuit Short To Battery
The airbag crash sensor #2 has a wiring problem where its power or ground line is accidentally connected directly to the battery voltage, creating a short circuit. Think of it like a garden hose that's punctured and spraying water everywhere instead of flowing through the normal path.
The ECU monitors the feed and return circuit voltage of crash sensor #2, expecting a stable signal within normal operating range. When the circuit shorts directly to battery voltage, the sensor line reads constant high voltage instead of the normal sensor signal pattern. The ECU detects this abnormal voltage condition and triggers the fault code.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| Sensor Circuit Voltage | 0.5-4.5V (variable with sensor state) | >12V (battery voltage detected) |
| Circuit Resistance | 2-10 kΩ (normal impedance) | <0.5 Ω (short to battery) |
Code B1905 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, B1905 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.