P0850: Park/Neutral Switch Input Circuit
Severity: medium
What it means: The engine or transmission computer sees a problem with the signal that tells it the car is in Park or Neutral.
Safe to drive? Use caution. The car may not start, may not shift out of Park, or may show the wrong gear. Don't drive if you can't trust the gear selection.
Common symptoms
- Check engine light
- No-start or trouble shifting out of Park
- Gear selector or transmission warning
Likely causes, ranked
- Faulty park/neutral or range switchShop
- Wiring or connector problemDIY
- Gear selector module faultShop
Vehicle-specific notes
- 2009–2015 Jaguar XF: On Jaguar Forums, an XF owner reported P0850 together with U101B while his rotary gear selector sometimes wouldn't rise. Read the full answer · Source
What it means: The engine or transmission computer sees a problem with the signal that tells it the car is in Park or Neutral.
Severity: Medium. Safe to drive? Use caution. The car may not start, may not shift out of Park, or may show the wrong gear. Don't drive if you can't trust the gear selection.
DIY or shop?
DIY for checking connectors and the battery; shop for range switch or selector diagnosis.
Before you replace parts
- Read all stored codes and freeze-frame data, not just this one.
- Check your VIN for recalls, service bulletins and extended coverage.
- Inspect wiring and connectors for the related sensor or part before buying parts.
- Clear the code only after a repair, then confirm it stays off.
Safety / mechanic note
Verify with a mechanic. A wrong park/neutral signal can affect starting and shifting. A code points to a circuit or system, not always a specific part.