P0A0C: interlock feedback is low when its source is active

P0A0C in the cited GM hybrid table concerns low feedback from the high-voltage interlock circuit. The published row checks sensed voltage as a fraction of its reference while the interlock source is actively supplying its nominal five-volt signal.

The source state is essential

A low interlock reading must be interpreted against the commanded source state. The monitor expects the sourced condition and detects a sensed fraction below its low threshold. A reading taken when the source is intentionally inactive does not reproduce that same check.

The row also qualifies the ordinary 12-volt supply. An interlock result and a low-voltage power problem should therefore be kept in context rather than treated as unrelated observations.

The code does not locate an open connection

The table establishes the monitored signal condition, but does not identify a particular cover, connector or interlock segment. Nor does it establish that the high-voltage bus is de-energized. Those conclusions require the vehicle-specific interlock diagnostic and isolation procedure.

The neighboring P0A0D monitor checks high feedback with separate sourced and unsourced conditions. Preserve the exact code and source state; merging both into a generic interlock complaint loses diagnostic information.

A qualified hybrid technician should document the source command, sensed feedback and supply state before choosing a repair. Never jumper an interlock to see whether the vehicle will operate. A passed signal check must be accompanied by the complete service verification required for the affected high-voltage system.

Application limits

Document-level 2015 GM diagnostic table; per-code vehicle/engine/calibration applicability not established.

Source

15OBDG01 Hybrid Diagnostics, physical PDF pages 553.