P0692: cooling-fan control stays high during an on command

P0692 identifies a high-voltage condition on the cooling-fan 1 relay's low-side control circuit. In the cited GM output-driver strategy, the voltage is judged while the driver is on, when a high reading indicates a short-to-power signature.

Electrical response is the key observation

The useful comparison is between the on command and the resulting control-circuit voltage. A high reading during the off state does not reproduce this particular fault criterion. The table describes a detection specification below 0.5 ohm between signal and controller power, not a direct resistance test to perform on an energized circuit.

Powertrain relay voltage must exceed 11 volts. Fifty failed samples out of sixty-three, at one hundred milliseconds per sample, form the documented decision. An isolated high sample does not establish completion of that decision.

Verify more than the visible fan

This monitor checks relay control integrity, not actual fan airflow. Visible fan operation and controller circuit status should therefore be treated as separate observations. The source does not establish the most likely failed part or require replacement of the fan motor.

Follow the exact vehicle's controlled fan-circuit procedure to resolve the mismatch and verify a passing on-state monitor under adequate supply voltage. Because fan commands may change during diagnosis, physical inspection must account for unexpected movement. The example is Type B over two trips; that classification is not a statement that a cooling complaint can be ignored.

Source and applicability

Documented monitors in gm-2025-03a, model year 2025. These are module/calibration examples; vehicle, engine and transmission applicability must be confirmed independently. GM 2025-03a, page 423.