P25B6: How the controller classifies a bank-two wastegate closed-side jam

P25B6 identifies the closed-side outcome of the bank-two wastegate jam monitor in this GM file. The controller requires substantial position-control deviation rather than diagnosing a jam from a single commanded-versus-actual snapshot. Its listed deviation band is ±40%, with timing beyond one second.

Position direction is not universal

The classification changes with the status defining whether zero-percent actuator position means closed. The table’s closed-side branch uses above 50% when that status is false and below 50% when it is true. Confirm the convention before treating a scan percentage as evidence that the wastegate is physically shut.

Evidence for a meaningful follow-up

The source requires an active actuator and excludes active testing, initial end-stop learning, a disabled power stage and a frozen-actuator cold-start state. A check outside those conditions may provide useful workshop information but is not automatically a pass of this monitor.

Capture the control error’s persistence and the position classification together. If the actuator is not eligible for monitoring, the absence of a new DTC cannot settle the issue. The code describes a control result and does not alone identify the mechanical or electrical component responsible for it.

Document scope and source

2025 GM 25OBDG07A Part 2 documented monitor only; its application-matrix filename join is unresolved. No model, engine or universal calibration applicability is inferred. These figures explain the cited controller logic, not a vehicle-specific repair instruction. Match the vehicle’s service information before applying them.

GM physical PDF page 866, GM physical PDF page 867.