Diagnostic article Generic OBD-II
P2777: Upshift paddle circuit high is a timed electrical limit
P2777 checks the upshift input above a high-voltage boundary, separately from whether the paddle is pressed or stuck.
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Documented application
2025 GM 25OBDG07A Part 2 documented monitor only; its application-matrix filename join is unresolved. No model, engine or universal calibration applicability is inferred.
The code alone does not identify a failed part or establish that a vehicle is safe to drive. Confirm the vehicle, reporting module and applicable service procedure.
P2777 is the electrical-high check on the upshift, or TAPUP, paddle input in this source. The row specifies voltage above 4,774 mV, 30 mV hysteresis and a failure interval of at least 150 ms. The controller is rejecting the electrical value rather than simply detecting a pressed switch.
Separate electrical and logical faults
A prolonged valid press belongs to a different monitor. P2777 does not become a stuck-paddle diagnosis merely because the driver was using the paddle when it appeared. Its relevant evidence is the input crossing the high electrical boundary for the specified interval.
Monitoring requires battery voltage above 8.75 V and below 18 V, outside cranking and stop-key states. P0882 or P0883 disables the check, linking interpretation to the controller’s power conditions.
A useful verification capture
Retain raw TAPUP input voltage and supply information during both release and operation. A normal switch-state label displayed later does not exclude an intermittent high electrical event. The 30 mV hysteresis belongs to the controller’s threshold handling and should not be confused with a component tolerance. Use applicable wiring information for isolation; this code alone does not prove that the paddle assembly is the failed part.
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.
Article source documents
Source checks describe how the text was prepared; they do not certify a diagnosis or confirm compatibility with every vehicle using this code.
Original code reference
Dictionary definition
Upshift Switch Circuit High
This definition retains its original catalog scope. The article above is limited to its explicitly documented application.
Reference scope
Generic OBD-II definition.
A manufacturer label does not establish the model, year, engine or module to which a diagnosis applies. Read the safety and diagnostic limits.
Definition source
- DTC Database: pinned community code definitions
Source checked · MIT