P277EClutch A Unexpected Mechanical Gear Disengagement
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- P277E reports that a gear on the shaft served by clutch A dropped out of engagement by itself while that clutch was carrying the drive, without any shift being commanded. GM's 2023 TCM tables for its dual-clutch gearbox run this check continuously: if the synchronizer of the driving gear shows a speed difference although the odd-gear clutch slips by less than 50 rpm, and this lasts 1000 ms, the code is stored as Type A with immediate MIL. Ford's 2024 OBD summary lists it for the TR9070 dual-clutch unit as an unintended disengagement on the shaft carrying the odd gears. P277F covers the even shaft, P2711 is the generic version without a clutch letter. Drivers notice a sudden loss of drive or a jump to neutral, usually followed by limp mode with some gears blocked.
- What you may notice
- Sudden loss of drive as if the gearbox had shifted into neutral
- Odd gears locked out, limp mode with reduced gear choice
- Warning lamp and transmission message in the cluster
- Likely causes
- LikelyWorn shift-fork detent or rounded engagement teeth on an odd gear
- PossibleShift rod drifting due to internal hydraulic leakage or a weak actuator
- PossibleFork end positions not relearned after repair or module replacement
- RareFaulty shaft speed signal making a slip appear at the synchronizer
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Workshop only · Usually a job for a workshop.Typical cost: €150 – €3,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.