P2B94: Why the bank 2 wastegate closed-stop reference fails

P2B94 is the bank 2 counterpart to a closed-stop feedback-learning check in the GM monitor. The relevant observation is the position signal averaged after the actuator is completely closed. Its purpose is different from a simple high or low input diagnosis during normal movement.

A reference point with prerequisites

The table marks failure when that average exceeds 3,768 mV or falls below 2,866 mV. It requires a fully closed state for 300 milliseconds, sufficient battery voltage and the stated engine-temperature and diagnostic-inhibit conditions. These are conditions for a particular controller comparison, not a universal specification for any wastegate position sensor.

The closed-state requirement is decisive. If the actuator has not reached the specified reference, a voltage reading cannot be compared meaningfully with the monitor's learned-stop band. A valid electrical input also does not guarantee that its reference at the stop is acceptable.

Turn the code into a focused question

Ask whether bank 2 reached the recognized closed state and what averaged feedback was recorded there. Preserve learning-related information before any reset, because an adaptation change can remove useful context without explaining why the earlier reference failed.

The source does not identify a specific failed part, adjustment or service campaign. Follow the application procedure for controlled movement and learning; do not force an actuator or apply the printed voltage limits as a mechanical adjustment target. Confirmation requires a completed closed-stop evaluation with acceptable feedback, rather than merely a normal position reading somewhere else in travel.

Source and applicability

2025 GM 07A-2 documented monitor only; module and calibration applicability must be matched to the vehicle. The application-matrix filename join remains unresolved; no model or engine fitment is inferred. GM PDF, page 863.