Vehicle Signal indicating Park While VSS Present
The vehicle's transmission is detecting it's in Park while the wheels are still spinning (VSS shows movement). It's like claiming the car is parked while the speedometer shows you're driving.
The ECM monitors Park switch status and Vehicle Speed Sensor (VSS) signals simultaneously. When Park is engaged, the ECM expects zero wheel speed; if VSS reports movement while Park is active, a fault is logged. This illogical condition triggers B2237.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| Park Switch + VSS State | Park engaged = 0 mph VSS signal | Park engaged + VSS >0 mph simultaneously |
| VSS Signal Duration in Park | <100ms noise tolerance | Sustained VSS signal >1 second while in Park |
Code B2237 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, B2237 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.