What does code P2777 mean?

Q: What does code P2777 mean?

Upshift Switch Circuit High. P2777 indicates that the transmission control module (TCM) has detected a high-voltage condition on the upshift switch circuit, which is part of the automatic transmission's manual shift control system. The TCM expects the switch to pull the signal line low when the driver requests an upshift, but instead it sees a voltage that remains near battery voltage, indicating an open circuit, a faulty switch, or a wiring problem.

DTC codes / P27xx · Transmission / P2777

P2777Upshift Switch Circuit High

P2777 indicates that the transmission control module (TCM) has detected a high-voltage condition on the upshift switch circuit, which is part of the automatic transmission's manual shift control system. The TCM expects the switch to pull the signal line low when the driver requests an upshift, but instead it sees a voltage that remains near battery voltage, indicating an open circuit, a faulty switch, or a wiring problem.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaTransmission

Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.