P0482: The third fan relay output has its own feedback check

The P0482 entry in GM's 2010 hybrid ECM section concerns cooling-fan relay control channel three. Its failure criterion is disagreement between the commanded driver state and actual control-circuit state. The number identifies a monitored output, not proof that the vehicle contains three separate fan motors.

Identify the channel before diagnosing the load

The document uses a 20-of-25 failing-sample decision at 250ms per sample while fan operation is being monitored. Run/crank voltage must satisfy the listed supply condition. A test performed with no relevant fan command may therefore miss the event that caused the code.

A temperature complaint and P0482 can coexist, but the code itself supplies electrical feedback evidence. It gives no airflow measurement and no criterion establishing a blocked radiator, weak motor or defective thermostat.

Follow the requested state

The useful question is whether relay-three feedback agrees with its own command through the event. Preserve the command state and any companion fan-output codes, then use the vehicle-specific diagram to identify what this third channel actually controls. Do not borrow relay-one or relay-two connector assignments from another vehicle.

The table's diagnostic timing is a monitor calibration, not permission to bypass a relay or run a fan through improvised wiring. A trained technician should follow the correct output-test procedure with the fan area clear. Verification should address the commanded channel and its feedback, rather than relying only on whether a fan can be made to spin.

Source and applicability

GM 2010 10OBDG10 Hybrid Diagnostics, only the cited controller and monitor. These are historical calibration examples; individual vehicle, engine and hardware applicability is not established. GM PDF, page 80.