P057D: a high brake-position input may represent an open circuit

P057D is a high-input brake-pedal position fault. In the cited GM strategy the monitor description specifically associates the high condition with an open circuit. That connection is useful because a high reported input does not necessarily mean the pedal has moved farther.

The sampled decision

The documented threshold is 95.00, with 20 failing samples out of a 32-sample window. No voltage unit is supplied for that threshold in the row. It should not be interpreted as a 95-volt circuit specification or used as a direct meter limit.

The fault reflects sufficient samples above the calibrated upper boundary. A live position value observed after the diagnostic has acted may no longer represent the input that triggered the decision, so retain the failure record before interpreting present data.

Why a zero reading can coexist with a high fault

GM specifies a fallback of zero-percent brake-pedal position after the high-input condition is detected. Thus, P057D and a current zero-percent position value are not inherently contradictory. The displayed value may be substituted by the controller.

For diagnosis, establish whether the relevant raw input is high and whether the current position parameter is a measured or default value. The summary does not identify a connector, wire, or mandatory replacement. A vehicle-specific brake-input procedure is needed to resolve the circuit condition and verify a passing monitor. Both cited calibrations describe a one-trip Type A response; clearing the code alone does not validate the underlying position measurement.

Source and applicability

Documented monitors in gm-2025-03a, gm-2025-04b, model year 2025. These are module/calibration examples; vehicle, engine and transmission applicability must be confirmed independently. GM 2025-03a, page 343. GM 2025-04b, page 562.