P07B8Transmission Park Position Sensor/Switch B Circuit/Open
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Can trigger limp mode
- Needs a drive cycle to confirm a fix
- How the car detects it
- With electronic gear selection the park position sensor/switch reports the park request or position. On GM's shift-by-wire selectors (2017 LaCrosse, XT4/XT5, Bolt EV, later SUVs and pickups) it is the P button, read by two redundant analog sensors A and B with separate 'released' and 'pressed' voltage zones. P07B8 means the circuit of the redundant sensor B is open. No manufacturer document available to us uses this code; GM covers an open analog circuit under its low and high codes (P07B9/P07BA). With one channel missing, the module can no longer cross-check the park request.
- What you may notice
- Check engine light, 'service transmission' or 'unable to shift' message
- Park cannot be selected by button, or the car will not shift out of P
- P button illumination off
- Likely causes
- LikelyWire or connector to the selector open
- PossibleConnector not latched
- PossibleSensor faulty
- Repair
- Medium · Usually a job for a workshop.Typical cost: €80 – €600
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.