Wiper Rear Mode Select Switch Circuit Failure
The rear wiper control switch isn't communicating properly with the vehicle's computer, like a broken remote control that can't send signals to the TV. The car can't tell if you want the wipers on, off, or set to intermittent mode.
The ECU monitors voltage signals from the rear wiper mode select switch to detect positions: off, intermittent, and on. It expects clean voltage transitions within specific ranges when the switch is actuated. If voltage stays out of range, fails to transition, or reads as open/shorted circuit, the fault is triggered.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| Switch voltage signal | 0V (off), 5V (on), variable (intermittent mode) | Out of range, no signal, or stuck voltage reading |
| Circuit continuity | Complete circuit path with resistance under 10 ohms | Open circuit (infinite resistance) or short to ground |
Code B1611 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, B1611 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.