P2669: Actuator supply B open-load can be detected at shutdown

In this GM transmission controller, P2669 maps the generic actuator-supply-B open-circuit description to high-side output two, or HSO2. The check runs at shutdown. With the high-side output disabled and a corresponding low-side output enabled, the load path should pull the monitored voltage down.

Why the code may appear later

If HSO2 remains above 40% of battery voltage, the controller stores an open-load result in nonvolatile memory. The next startup reads that result and sets the DTC. Consequently, the moment the driver notices the code can be later than the actual electrical test.

The source requires a 60 ms confirmation period and less than 1.5 V of battery change during the test. P0882 or P0883 disables the check, so a voltage-related inhibit can affect whether it ran.

Verify the shutdown event

A normal running voltage is not a repeat of this shutdown load-path test. Preserve the stored test result and evidence that the shutdown path completed with suitable supply conditions. Use the controller-specific circuit information to identify HSO2 and its load paths. The summary’s open-load classification does not automatically prove an open external wire or a particular failed actuator.

Document scope and source

2025 GM 25OBDG07A Part 2 documented monitor only; its application-matrix filename join is unresolved. No model, engine or universal calibration applicability is inferred. These figures explain the cited controller logic, not a vehicle-specific repair instruction. Match the vehicle’s service information before applying them.

GM physical PDF page 936.