Diagnostic article Generic OBD-II
P2BA2: The cited pump-stalled row actually checks speed while commanded off
Understand the off-state running indication described for P2BA2 and why it differs from a conventional zero-speed stall diagnosis.
Read before applying this article
Documented application
2025 GM 25OBDG03B documented monitor only. Vehicle, engine and calibration applicability must be confirmed from the matching service information; no model fitment is inferred.
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.
P2BA2 is headed coolant pump stuck/stalled, but the actual GM algorithm on this page checks the pump while it is commanded off. It looks for reported speed that remains characteristic of operation. That explicit behavior must not be rewritten as a test for zero speed under an on command.
The off-state qualification is decisive
The monitor requires pump disablement or a command between zero and four rpm for at least three seconds. Its failure criterion is feedback at or above 10 rpm. Thus, the meaningful contradiction in this document is continued speed reporting despite an established off request.
Supply must exceed the documented enable threshold and relevant pump-speed feedback faults must be absent. Invalid feedback would undermine the inference that the pump is actually operating when it should be off.
Verify persistence before assigning a cause
The table requires eight seconds of failure within a ten-second window. A short coast-down indication immediately after switch-off is not the same as the qualified persistent result. Preserve command history and reported speed through both the initial off interval and the failure window.
The source does not resolve why its stuck/stalled heading differs from this off-state algorithm. It also does not prove whether the pump keeps turning or the feedback incorrectly reports speed. Those distinctions require matching service information; the code alone does not justify a pump replacement.
Source and applicability
2025 GM 25OBDG03B documented monitor only. Vehicle, engine and calibration applicability must be confirmed from the matching service information; no model fitment is inferred. These criteria explain controller logic, not a complete repair procedure. 25OBDG03B, PDF page 888.
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
Engine Coolant Pump Stuck/Stalled
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