P0D40: high charger AC peak voltage is a fast circuit check

P0D40 identifies the high side of the charger's AC input-voltage circuit evaluation in this GM document. It concerns the reported AC peak voltage, rather than the low-voltage battery bus or a traction-battery state-of-charge estimate.

The high and low tests have different timing

The cited high-voltage threshold is greater than 422 V. Failure requires 160 milliseconds of that condition within a 200-millisecond window. AC must be present, and the bulk-voltage-dropping state must be false.

The adjacent low-input-voltage monitor uses a much longer observation period. Consequently, the timing assigned to P0D3F cannot simply be reused for P0D40. Here, an acceptable reported peak voltage for 200 milliseconds satisfies the stated pass branch. The diagnostic is classified as one-trip Type A.

What the record can establish

A useful fault capture contains the peak-voltage report and the input-state flags at the same time. Comparing a peak measurement with an unrelated RMS meter reading would mix different quantities and can create a misleading explanation of the fault.

This is a circuit-range finding, not proof that an external supply exceeded its rated voltage. A sensing problem can also produce an excessive reported value; the table provides no component isolation test. Follow the correct charger procedure to distinguish those possibilities. Do not use this historical limit as permission to probe a charging inlet or internal high-voltage circuit. Qualified personnel must establish the proper measurement method and safe equipment state.

Source and applicability

GM 2015 15OBDG01 Hybrid Diagnostics, only the cited EACCM monitor and calibration. Per-code vehicle and engine applicability has not been established; these historical thresholds are not universal service specifications.

General Motors source, physical page 741