Diagnostic article Generic OBD-II
P07BA: Park-button switch B exceeds the high-signal boundary
P07BA records a high Park-button switch B signal in the documented 25OBDG04B monitor.
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Documented application
Documented 2025 GM diagnostic parameter monitor in 25OBDG04B.pdf; model, engine and calibration applicability require vehicle-specific confirmation.
The code alone does not identify a failed part or establish that a vehicle is safe to drive. Confirm the vehicle, reporting module and applicable service procedure.
P07BA is the high-circuit code for Park-button switch B in GM's 25OBDG04B table. The monitored quantity is the shifter's measured B-channel signal. It is not a measurement of parking-lock engagement force or transmission hydraulic pressure.
Boundary and persistence
The published high threshold is 236.00 or greater, using an unspecified signal scale. The table requires 20 failures within 25 samples before qualification. It does not print a sampling interval on this page, so the counter alone cannot establish a precise number of milliseconds.
Type B reporting over two trips is listed separately from that sample counter. Those are different stages: samples describe the monitor's failure qualification, while trips describe the reported diagnostic class. Treating “two trips” as the time required for an electrical excursion would confuse them.
Applying this monitor carefully
The calibration must enable the test. Compare the B-channel measurement with its recognized states and diagnostic status using the correct signal scaling. A Park request shown elsewhere in scan data does not independently prove that switch B remained within its permitted electrical range.
Confirmation requires an enabled B-channel check that no longer accumulates the qualifying high readings. The source does not identify the responsible component or provide a replacement procedure. This article covers the 25OBDG04B implementation. Its signal scaling, sample qualification and trip policy must be confirmed against the installed controller before the numerical threshold is applied to a vehicle.
Source: GM monitor, PDF page 650.
Article source documents
Source checks describe how the text was prepared; they do not certify a diagnosis or confirm compatibility with every vehicle using this code.
Original code reference
Dictionary definition
Transmission Park Position Sensor/Switch B Circuit High
This definition retains its original catalog scope. The article above is limited to its explicitly documented application.
Reference scope
Generic OBD-II definition.
A manufacturer label does not establish the model, year, engine or module to which a diagnosis applies. Read the safety and diagnostic limits.
Definition source
- DTC Database: pinned community code definitions
Source checked · MIT