P0354: Coil D open-circuit interpretation needs the actual driver mapping

P0354 is cataloged as ignition coil D primary control circuit/open. The GM source row describes an open-circuit test at an ignition-coil low-side driver, yet its strategy text calls the coil “C.” The relationship between that internal letter and the generic designation must be confirmed before assigning a cylinder or connector.

The verified test is an off-state electrical check

The controller evaluates low voltage while the driver is off, interpreting that feedback as an open-load condition. The row specifies a 0.4-second detection interval and two-trip reporting. It also requires ignition synchronization and engine speed above 1,400 rpm.

A change of more than nine ignition-counter counts is listed to ensure all cylinders have fired at least once. This is a meaningful eligibility detail: an isolated key-on output reading is not the same as the qualified running check.

Keep the uncertainty at the hardware boundary

The source’s upper supply limit is unusually large and is not adopted as a practical test specification. More importantly, the mapping from the generic D label to the source’s internal C wording has not been established here.

Preserve the driver fault status, synchronization and ignition-event context, then confirm the installed calibration’s mapping in service information. The monitor cannot identify whether an interruption is in the load, wiring or driver. It provides electrical evidence for investigation, not a direct instruction to replace a particular coil.

Source and applicability

This explanation covers the cited GM monitor, not every vehicle carrying this code. The application-matrix filename does not resolve cleanly to this file, so no model or engine fitment is assigned. GM diagnostic table, PDF page 700.