Park/Neutral Position Switch Circuit Malfunction
Issues with the Park/Neutral position switch circuit.
Heads up: this code wasn't in our hand-written library yet, so DiagCoach AI built this page on the fly. Double-check critical specs against service info before condemning parts.
What it means (plain English)
The Park/Neutral position switch tells the transmission whether the vehicle is in Park or Neutral. If this switch malfunctions, the engine might not start or the transmission may not shift properly.
What the computer is actually seeing
The engine control module (ECM) monitors the voltage at the Park/Neutral position switch. It expects specific voltage levels when in Park (typically close to battery voltage) and Neutral (also close to battery voltage).
What a healthy reading looks like
When in Park or Neutral, voltage should be between 10 to 14 volts. If it's below 10 volts or floating, there’s an issue.
Guided diagnostic — the DiagCoach way
Don't just throw parts at it. Walk through these in order — each step tells you whether to keep going or stop and fix what you found.
- 11. Inspect the wiring and connectors to the Park/Neutral position switch for fraying or corrosion. If any damage found, repair it and retest.
- 22. Check the voltage at the Park/Neutral position switch with a multimeter. In Park/Neutral, you should see 10-14 volts. If not, continue to step 3.
- 33. Test the Park/Neutral position switch for continuity with the transmission in both Park and Neutral. If it fails to switch properly, replace it and clear the code.
- 44. If the switch tests fine, inspect the vehicle's transmission harness for shorts or breaks; repair as necessary and retest.
Common causes
- Faulty Park/Neutral position switch
- Wiring or connector issues
- Corroded connections
- Incorrectly adjusted switch
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It's best to fix it soon; you may experience starting issues or the vehicle may not shift into gear.
Will this code come back after resetting?
If the underlying issue isn't fixed, it will likely return.
Why does this code show up with others?
Codes like P0851 and P0852 indicate similar circuit issues, often from the same faulty switch or wiring.
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