P07BB: Park-button switch B has an unrecognized intermediate reading

The defining feature of P07BB in the reviewed GM table is an ambiguous Park-button state. Switch B's measured signal falls outside both its pressed and released zones, even though that condition differs from the dedicated circuit-low and circuit-high checks.

An intermediate interval

The source defines the malfunction interval as greater than 184.00 and less than 188.00. It gives no voltage unit, so these are controller-signal values rather than a ready-made meter specification. A reading within this interval can be problematic despite not being an extreme high or low value.

The diagnostic needs 400 failing samples in a 480-sample window. That persistence criterion is part of the distinction between a fleeting transition through an intermediate value and a reportable performance fault. This page does not provide a sampling period, so an exact elapsed failure time cannot be calculated from it alone.

Related codes affect eligibility

The enable information references P07B9 and P07BA, switch B's low and high faults, as codes not set. Calibration enablement is also required, and reporting is Type B over two trips. Their presence should therefore be considered before assuming this performance test has completed normally.

For confirmation, examine the B-channel value and the interpreted button state over actual transitions. The intended result is reliable recognition of the permitted states under an enabled diagnostic. P07BB alone does not demonstrate a failed parking lock or identify a replacement assembly. The thresholds remain limited to this 2025 GM monitor pending vehicle-specific applicability checks.

Source: GM monitor, PDF page 651.