P062B: fuel-injector driver integrity has several internal failure paths

P062B identifies internal fuel-injector control performance. The GM summaries cover faults that can compromise driver operation or controlled fueling, including internal communication, initialization, supply and configuration checks.

Boost voltage is an internal driver quantity

The 03A example lists internal ECU boost voltage at or above 90 volts or at or below 40 volts, plus not-ready and uninitialized driver states. Those are not fuel-pressure limits or ordinary battery-voltage specifications. The voltage and readiness paths use their own sample decisions and require relevant supply conditions with the engine not cranking.

The 04B example adds detail such as failed chip tests, microcode loading and SPI communication. Its initialization-related branch also requires boost voltage to have reached 40 volts at least once. A driver that has never reached that prerequisite cannot be interpreted using the same enabled decision without checking the calibration.

What the code can establish

The code identifies a fault category inside injector control, not a named cylinder injector or a proven mechanical fuel leak. Preserve driver status, voltage context and any available internal subtype before choosing a diagnostic path.

Because injector drivers involve elevated voltage and controlled fueling, use the appropriate professional procedure; do not probe or bypass driver outputs based on this summary. Verification needs the applicable internal checks to pass after the cause is addressed. Neither table provides a universal injector replacement or controller-reflash remedy.

Source and applicability

Documented monitors in gm-2025-03a, gm-2025-04b, model year 2025. These are module/calibration examples; vehicle, engine and transmission applicability must be confirmed independently. GM 2025-03a, page 410. GM 2025-04b, page 1227.