P0E39: converter voltage B high requires channel-specific evidence

P0E39 detects an excessive raw converter actuator voltage-2 reading in the cited ECM. The documented threshold is above 28 volts, and the strategy describes the voltage-sensor B circuit's short-to-battery diagnosis.

Identify the quantity before interpreting the fault

This is channel 2 of the actuator-voltage monitoring described by the table. It is not automatically a battery-terminal overvoltage result or a measurement of an unspecified high-voltage traction bus. The source supplies no basis for those broader interpretations.

The controller evaluates 320 failures out of 400 samples at a 12.5-millisecond loop rate, with battery voltage at least 6.60 volts. An intermittent high period may have ended before a technician reads the current PID, so preserve event status and recorded values where available.

Architecture determines whether the test runs

The shown 03A configuration uses the sensor-bus relay on/no-fault branch. A separate Global-B branch uses run/crank or accessory power, but it is not the selected architecture value on this page. A test performed with the wrong enabling assumption may never exercise this monitor.

Verification should show raw channel 2 stays within its valid electrical behavior and that the enabled high-input diagnostic passes. A normal channel-1 reading or successful restart cannot substitute for that evidence. The table does not specify converter internals, a replacement part or a safe probing method; use the vehicle-specific professional electrical procedure.

Source and applicability

Documented monitors in gm-2025-03a, model year 2025. These are module/calibration examples; vehicle, engine and transmission applicability must be confirmed independently. GM 2025-03a, page 449.