P0850
Park/Neutral Switch Input Circuit
Transmission controls
Generic OBD-II
Medium
What it means
P0850 flags a problem in the park/neutral switch input circuit — the switch that tells the car it's in Park or Neutral so it can start safely. A fault can leave the engine unable to start, or in rare cases let it crank while in gear. The car drives normally once started, but this safety-related circuit is worth fixing promptly.
Medium
Can I keep driving? The engine may refuse to start unless in Park or Neutral, and the switch is a safety device — have it fixed promptly.
Common symptoms
What you'll notice
- Check-engine light on
- Engine won't start, or only starts in certain shifter positions
- Wrong gear position shown on the dash
- Possible risk of starting while in gear (safety concern)
Common causes
Most likely first
- Faulty park/neutral (transmission range) switchLikely
- Misadjusted range switchCommon
- Wiring or connector fault in the switch circuitCommon
- Loose or corroded connectionsLess often
- Failed TCM/PCM — least likelyLess often
How to diagnose & fix
Work through it in order
- Confirm the code and check the park/neutral switch adjustment.
- Inspect the switch connector and wiring for damage or corrosion.
- Test the switch's signal in each shifter position against spec.
- Replace the range/park-neutral switch if it fails.
- Clear the code and verify the engine starts only in Park or Neutral.
FAQ
Quick answers
Is it safe to drive with P0850?+
The car drives normally once started, but this is a safety circuit — a fault can prevent starting or, rarely, let the engine crank while in gear. Fix it promptly.
Can I just clear P0850?+
It returns until the switch, its adjustment, or the wiring is repaired.
Related codes
Often seen with P0850
Read & clear P0850 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX