Wiper Rear Disable Switch Circuit Failure
The rear wiper disable switch circuit isn't communicating properly with the vehicle's control module, similar to a light switch that's broken so the system can't tell if it's on or off. The ECU detects an open or short circuit in the wiring or switch that controls the rear wiper's off position.
The ECU monitors the voltage signal from the rear wiper disable switch circuit to verify proper operation. It expects a specific voltage pattern when the switch is activated and released. If the signal stays outside normal range or fails to transition properly, a circuit failure is detected.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| Switch Signal Voltage | 0.5V to 4.5V with proper transitions | Stuck at 0V or 5V, no signal detected, or erratic transitions |
| Circuit Resistance | 50Ω to 1000Ω depending on switch state | Open circuit (infinite resistance) or shorted to ground (near 0Ω) |
Code B1615 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, B1615 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.