Wiper Park Sense Circuit Failure
The wiper system has lost its ability to detect when the wipers have returned to their resting position, like a car that forgets where 'home' is. The ECU can't confirm the wipers parked correctly, so it can't control them properly.
The ECU monitors the park sense switch or position sensor circuit, which signals when wipers reach their home/park position. It expects to receive a voltage signal transition when wipers complete their cycle. If this signal is absent, delayed, or noisy, the ECU cannot confirm proper park position and triggers the fault.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| Park Sense Voltage | Clean transition from 5V to ground (or 0V to 5V) at cycle end | No signal transition, stuck voltage, or open/short circuit detected |
| Signal Timing | Park signal received within expected wiper cycle duration | Signal absent or arrives outside acceptable timeframe |
Code B1446 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, B1446 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.