Transmission Park Position Sensor/Switch B Circuit/Open
Park position sensor/switch B is the redundant/secondary park-confirmation sensor — used in shift-by-wire systems for safety, so a single sensor failure cannot strand the vehicle in Park or hide a non-Park condition. With B open the TCM falls back to sensor A only.
Affected components
- Park position sensor b
- Wiring harness
Common causes
- High likelihood: Open wire or unplugged sensor
- Low likelihood: Pin pushed back out of connector body
- Low likelihood: Cracked solder joint inside the module or sensor
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
Related codes
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.