What does code P277E mean?

Q: What does code P277E mean?

Clutch A Unexpected Mechanical Gear Disengagement. P277E indicates that the transmission control module (TCM) has detected an unexpected mechanical disengagement of clutch A, meaning the clutch stopped transmitting torque when the computer commanded it to stay engaged. The TCM monitors input and output shaft speeds and compares them to the expected ratio for the commanded gear; when the ratio deviates beyond a calibrated threshold, it logs this code because the clutch slipped or released without a command.

DTC codes / P27xx · Transmission / P277E

P277EClutch A Unexpected Mechanical Gear Disengagement

P277E indicates that the transmission control module (TCM) has detected an unexpected mechanical disengagement of clutch A, meaning the clutch stopped transmitting torque when the computer commanded it to stay engaged. The TCM monitors input and output shaft speeds and compares them to the expected ratio for the commanded gear; when the ratio deviates beyond a calibrated threshold, it logs this code because the clutch slipped or released without a command.

SystemPowertrain

Code typeGeneric (all makes)

SeverityHigh

Fix difficultyProfessional

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.