P07B4Transmission Park Position Sensor/Switch A Circuit High
- 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. P07B4 means sensor A reads above its valid zones: GM flags above 853 counts (83.3 % of 5 V), the ICCM above 70 %, after two trips. A short to positive or an open ground is typical. A GM bulletin for the 2017 LaCrosse, XT5 and Bolt EV lists P07B4 when the selector knob is not fully seated or the connector at the shifter is not latched – check that first.
- 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
- LikelySignal shorted to positive or ground open
- PossibleSelector knob not fully seated or connector not latched
- PossibleSensor in the P button faulty
- RareSelector or control module
- 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.