P2154: Injector 3 high-side circuit indicates unwanted power

P2154 is a short-to-power diagnosis for injector 3's high-side circuit in this GM source. The catalog's group C supply-high wording is broader; the OEM row provides the injector number only for its own documented implementation.

High while off is the relevant finding

The output driver assesses voltage when it is powered off. A signal outside the accepted off-state range indicates unwanted power. The table specifies a signal within one volt of controller power as the controller's short-to-power signature.

This makes command state essential. An electrical reading near supply during a normal powered event is not sufficient evidence of P2154. Conversely, an apparently normal average voltage can conceal off-state persistence if the measurement does not resolve the event being evaluated.

What the code can and cannot establish

The battery must provide at least 11 V, and the specified P062B failure states must be absent for monitoring. The decision uses 10 failing samples out of 20, with 100 milliseconds between samples. These prerequisites and the sampling window should accompany any attempt to reproduce the fault.

An off-state electrical fault does not, by itself, prove that the injector is mechanically stuck or that fuel pressure is excessive. Those conclusions require separate tests. A suitable verification follows the vehicle's injector-circuit procedure, confirms acceptable driver-off behavior and allows the monitor to complete again. The source lists a Type A, one-trip response, but offers no component location, pin assignment or mandatory replacement.

Source and applicability

The thresholds and component mapping apply only to the documented monitor, pending vehicle and calibration confirmation. GM diagnostic table, PDF page 608.