Illuminated Entry Relay Short To Ground
The illuminated entry relay has an electrical short circuit directly to ground, preventing it from operating normally. Think of it like a light switch with a broken wire touching the ground, so the circuit always completes even when you don't want it to.
The ECU monitors the illuminated entry relay's control circuit voltage to verify it can switch on and off properly. When a short to ground exists, the relay coil cannot build sufficient magnetic field, and the control circuit voltage drops below the minimum threshold needed for relay activation.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| Relay Control Circuit Voltage | 12V when energized, 0V when de-energized | Voltage remains below 2V or cannot reach threshold due to short |
| Circuit Resistance | Relay coil resistance 70-100 ohms | Resistance drops below 5 ohms indicating short path to ground |
Code B1374 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, B1374 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.