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.

Real-world scan data

Seen in

764

scans in the past year

Found in

0.1%

of scans

0.2%

of scans that found faults

Appears alongside · share of P0850 scans

P0704in 79.7% of scans

P0421in 74.5% of scans

P2201in 73.4% of scans

Figures reflect only diagnostic scans recorded through our own apps and tools. Cars are typically scanned because a symptom or warning light prompted it, so these counts describe our scan records — not the incidence of faults in any model, and not the quality, reliability, or safety of any vehicle. No comparison between manufacturers or models is implied. All trademarks belong to their respective owners; no affiliation or endorsement is implied.

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.

Read & clear P0850 yourself

Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.

▶ Get it on Google Play

✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX