What P07B2 means
With electronic gear selection the park position sensor/switch reports the park request or position.
How the engine computer detects it
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. P07B2 means the circuit of sensor A is open: the module sees a missing or undefined signal. No manufacturer document available to us uses this code; GM covers an open analog circuit under its low and high codes (P07B3/P07B4), which CARB allows when an open cannot be told apart from an out-of-range value. Park may then not be selectable by button.
Written from public technical sources and not yet checked by a mechanic. How we write these pages
Symptoms
- 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
Common causes
- Wire or connector to the selector open Most likely
- Connector not latched Possible
- Sensor faulty Possible
How to diagnose P07B2
- Read every stored code with an OBD-II scanner. If misfire or fuel trim codes are there too, fix those first: they often cause this one.
- Inspect the parts involved: park position sensor, electronic range selector, sensor wiring, transmission control module.
- Work through the causes above from most to least likely, cheapest checks first.
- Clear the code and drive a full drive cycle to confirm the repair held.
Reading the code
- P
- Powertrain
- 0
- Generic (SAE) code
- 7
- Transmission
- B2
- Specific fault
Questions drivers ask
Can I drive with code P07B2?
If the car shifts normally, drive gently to a shop. If it's stuck in one gear, slips, shifts harshly or won't move out of Park, don't drive it: have it towed.
Will P07B2 clear by itself?
The light can go off after several drive cycles without the fault, but the code returns if the cause is still there. After a repair, the readiness monitors need a full drive cycle before an inspection.
This page is general information, not a substitute for a professional diagnosis. Repair costs are rough estimates for parts and labor and vary by vehicle and region.