P0AD9: positive-contactor driver response does not match the command

P0AD9 in the cited GM hybrid table concerns the positive battery-contactor control circuit. The controller compares the commanded driver state with the observed circuit response, using voltage feedback when off and current feedback for an on-state open-load check.

Circuit integrity is not contact position

This monitor evaluates the control side. The same document separately monitors whether a contactor is stuck closed by comparing bus and battery voltage. A driver-circuit result therefore should not be treated as direct proof that the high-voltage contacts are welded or physically open.

The strategy explicitly states that this check cannot detect a short-to-ground fault. That limitation matters: absence of P0AD9 does not establish that every possible circuit defect has been excluded.

Match feedback to the commanded state

An off-state voltage observation and an on-state current observation answer different questions. Preserve the command when reviewing the feedback; one unexplained reading cannot reconstruct the monitor's decision.

GM requires adequate 12-volt supply and counts repeated failures over its defined sample window. The row uses a one-trip classification for the positive-contactor result.

The source does not identify a failed coil, harness segment or controller driver. Physical testing must follow the high-voltage isolation and control-circuit procedure for the vehicle. Do not energize or bridge a contactor experimentally. Verify both valid driver response and any separate contactor-state checks required by the service instructions after the demonstrated defect is repaired.

Application limits

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

Source

15OBDG01 Hybrid Diagnostics, physical PDF pages 554.