Park/Neutral Switch Input Circuit Low
Voltage on the park/neutral switch input is below the expected window. Wire shorted to ground or switch stuck closed.
Affected components
- Park neutral switch
- Wiring harness
- Ecm
Common causes
- High likelihood: Wire shorted to ground
- Medium likelihood: Switch stuck closed
- Low likelihood: Connector pins corroded - high contact resistance
Possible symptoms
- Check engine or transmission warning light on
- Harsh, delayed, or missing shifts
- Possible limp mode (locked in one gear)
- Slipping or shuddering during gear changes
Diagnostic notes
- The malfunction indicator lamp may illuminate
Sources
Diagnostic information is provided for reference only. Confirm the code with a compatible scan tool and follow the vehicle manufacturer's service procedures before replacing components.