Wiper Rear Mode Select Switch Circuit Open
The rear wiper control switch circuit has an open connection, meaning the electrical signal between the switch and the vehicle's computer is broken. It's like a light switch with a cut wire—the switch works, but the signal never reaches its destination.
The ECU monitors voltage levels on the rear wiper mode select switch circuit to detect valid switch positions (off, intermittent, continuous). An open circuit causes the signal voltage to remain at an abnormal level or fail to transition between expected states, triggering the fault code.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| Switch circuit voltage | 0-5V with proper transitions between modes | Open circuit or no signal detected |
| Circuit continuity | Continuous path with varying resistance per mode | Infinite resistance/open circuit |
Code B1612 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, B1612 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.