P0850 Code: Park/Neutral Switch Input — Causes & Fix
P0850 means a fault in the park/neutral position (PNP) switch input — the signal that confirms the transmission is in Park or Neutral for starting.
- Applies to
- All OBD-II vehicles (any make or model)
- Est. repair cost
- $30 – $400
- Time to fix
- 1–4 hours
What it means
Causes include a failed/misadjusted PNP switch, wiring faults, or a linkage problem. P0850 is a generic OBD-II code defined in the SAE J2012 standard, so it applies to virtually any 1996-or-newer OBD-II vehicle regardless of make. Fix the underlying fault, then clear the code with an OBD-II scan tool — it will return if the problem isn't resolved.
Symptoms
- Check engine light on
- No-crank in Park/Neutral (or cranks in gear)
- Wrong gear indication
How to fix it
- 1
Check the PNP switch
1. Inspect and adjust the park/neutral switch. 2. Confirm it changes state with gear selection.
- 2
Replace and clear
1. Replace a faulty switch, then clear the code.
Frequently asked questions
Why won't my car start with P0850?
The park/neutral switch is a safety input for starting. If it can't confirm Park/Neutral, the starter may be disabled.
Last updated July 19, 2026
Guidance only — always consult a qualified professional or the official service manual before carrying out repairs.