P24A5: The EGR bypass fails to return after drive is removed

P24A5 is a default-return check in this GM EGR cooler-bypass system. The expected unpowered position is fully closed in cooling mode. The controller looks for feedback that remains away from that position after electrical drive has been removed, which is different from tracking a moving target during normal powered control.

Allow for the spring-return interval

The documented position threshold is above 15%. A wait exceeding one second after driver shutoff gives the spring an opportunity to return the mechanism. Comparing feedback immediately at shutdown would omit that explicit part of the test.

The row also names P245B as already set and describes requirements for the diagnostic system and usable position/control information. Those dependencies should be retained with the fault record rather than replaced by a general assumption that any key-off position is a valid test.

Interpret a missing default position carefully

GM lists no additional debounce once the eligible error is present. That does not remove the preceding shutdown wait or other enables. The useful distinction is between a valve that has not yet had time to return and one still reporting the wrong default position after the qualifying interval.

Preserve the drive-off time, feedback trajectory and related faults. The monitor supports investigating a failed return, but the table alone cannot distinguish a mechanical obstruction from misleading feedback or another system condition. A matching service procedure is needed before attributing the result to a particular part.

Source and applicability

2025 GM 25OBDG04A 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. 25OBDG04A, PDF page 1219.