Wiper Washer Pump Motor Relay Coil Circuit Open
The wiper washer pump's relay coil circuit has an electrical break, preventing the relay from activating. Think of it like a broken switch that can't send power to turn on the windshield washer pump.
The ECU monitors the voltage and continuity of the wiper washer pump relay coil circuit. When the washer command is sent, the ECU expects to detect proper coil current draw through the relay. An open circuit prevents current flow, triggering the fault.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| Relay Coil Current | 200-600 mA when activated | 0 mA or below detection threshold |
| Circuit Voltage | 12-14V supplied to relay | No voltage drop across coil |
Code B1459 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, B1459 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.