P2009: swirl-motor circuit low is identified by H-bridge overcurrent

P2009 is a low-circuit fault for the intake-runner swirl motor in the reviewed GM table. The monitor describes commands shorted to ground, but its measured failure criterion is excessive current through the H-bridge switches. “Low” therefore does not mean that this page measures a low position-sensor voltage.

The powered electrical test

The H-bridge driver must be on, and hardware diagnostic information must be determinate. Current above 8 amperes is the listed malfunction threshold. This is an energized driver test, unlike the neighboring open-circuit monitor that operates with its driver off.

The powertrain-relay supply must exceed 11 volts, the engine must be outside the cranking phase, and calibration must enable the diagnostic. An observation made during a weak-supply crank does not meet these documented conditions.

What the fault proves

The controller requires 240 failures in a 300-sample window on a 12.5-millisecond task and lists Type B, two-trip reporting. This establishes a sustained hardware short-to-ground indication under the specified conditions; it does not locate the exact short or prove that the entire manifold assembly is defective.

Verification should examine the enabled powered-driver result and whether the overcurrent indication returns. A normal unpowered resistance reading alone does not reproduce that operating check. Conversely, an unrelated flap-position deviation should not be substituted for the electrical evidence. The monitor facts here are bounded to the 2025 GM swirl-motor implementation; component identification and isolation require the vehicle's service procedure.

Source: GM monitor, PDF page 1380.