Wiper Rear Motor Run Relay Circuit Failure
The rear wiper motor relay isn't working properly, so the ECU can't control the rear windshield wiper. It's like a light switch that's broken—the power is there, but the switch can't turn the motor on or off.
The ECU monitors the rear wiper relay circuit for proper voltage and current flow when the wiper switch is engaged. It detects open circuits, shorts, or relay coil failures by measuring continuity and voltage at the relay control pins. If resistance or voltage readings fall outside normal operating thresholds, the fault code triggers.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| Relay Coil Voltage | 12V ±10% when activated | Below 10.8V or above 13.2V, or 0V when commanded |
| Motor Circuit Continuity | Continuous path with <1Ω resistance | Open circuit (infinite resistance) or short to ground |
Code B1244 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, B1244 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.