P284AShift Fork B Stuck
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- P284A is stored when fork B stays put although the transmission module commanded a move, for instance from neutral toward an engaged gear or back. Published strategies avoid this code. Ford's 2024 summary for the TR9070 dual-clutch box diagnoses the same symptom per gear rather than per fork, with failure-to-engage codes such as P073F and failure-to-disengage codes such as P072B, while GM's Corvette software folds a motionless rod into its position-sensor consistency checks. The CARB 13 CCR 1968.2 functional check of transmission components covers the case either way. For the driver, the gears carried by fork B disappear; if the fork hangs in an engaged gear, the module may have to drive around it on the other shaft. Inspection usually means opening the gearbox.
- What you may notice
- Gears of fork B missing or a gear stays engaged
- Warning lamp and emergency mode
- Rough starts or lack of drive in some gears
- Likely causes
- LikelyFork B actuator, solenoid or hydraulic supply failing to apply force
- PossibleSynchronizer of fork B gears jammed or damaged
- RareContaminated fluid restricting the fork B actuator
- 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: €300 – €4,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.