Battery Power Relay Circuit Open
The battery power relay that supplies electrical power to vehicle systems has an open circuit, meaning the connection is broken like a cut wire. The ECU cannot detect proper voltage through the relay circuit, so it triggers this fault code.
The ECU monitors the battery power relay circuit by measuring voltage presence and continuity through the relay coil and contacts. It expects a stable voltage signal when the relay is commanded on; if voltage drops below threshold or remains absent, the fault is detected.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| Relay Circuit Voltage | 12-14V when relay engaged | Below 10V or open circuit detected |
| Circuit Continuity | Continuous path with low resistance | Open circuit or resistance exceeds 5 ohms |
Code B1293 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, B1293 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.