P2857Clutch A Pressure Engagement Performance/Too Low
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- P2857 reports that clutch A did not build up enough holding force when the control unit asked it to engage, so the expected ratio or torque transfer never appeared. Mitsubishi documents it for the CVT with two-speed auxiliary gearbox fitted to Mirage and Mirage G4 models from 2014 to 2022: while that gearbox is shifted into its first ratio, a measured ratio of 2.232 or more for 2 s counts as a fault, provided the pedal is at least 7.8 % open, the engine turns 450 rpm or more and D or B is selected. Nissan lists the same number as a clutch A pressure fault on the Kicks and Versa CVT, and Mercedes-Benz uses it on the 8G-DCT when multidisk clutch 1 fails to close. Drivers typically notice slipping, a flaring engine on take-off or a reduced-power mode.
- What you may notice
- Engine speed flares on take-off without matching acceleration
- Hesitation or reduced power, transmission emergency mode
- Warning lamp with stored transmission code
- Likely causes
- LikelyControl valve (valve body) not delivering the commanded apply pressure to clutch A
- PossibleWorn clutch A linings or leaking piston seals
- PossibleLow, aerated or aged transmission fluid
- 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 – €4,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.