P2857
Clutch A Pressure Engagement Performance/Too Low
Transmission controls
Generic OBD-II
Medium
What it means
P2857 means clutch A isn't getting enough apply pressure to engage properly, so it slips instead of locking up cleanly. The controller sees engagement performance below target. Common causes are low line pressure, a worn clutch, a faulty pressure control solenoid, or low/degraded fluid. Slipping builds heat fast, so the transmission should be serviced before the clutch is ruined.
Medium
Can I keep driving? Limited — low clutch apply pressure lets the clutch slip, which overheats and wears it, so avoid heavy loads and get it serviced soon.
Common symptoms
What you'll notice
- Check-engine light on
- Clutch slip — engine revs climb without matching acceleration
- Delayed or soft engagement
- Shudder on take-off; possible limp mode
Common causes
Most likely first
- Low transmission line/clutch apply pressureLikely
- Worn clutch A friction materialCommon
- Faulty pressure control solenoid for clutch ACommon
- Low or contaminated transmission fluidLess often
- Valve body wear or internal hydraulic leakLess often
How to diagnose & fix
Work through it in order
- Check transmission fluid level and condition first.
- Read freeze-frame and compare commanded vs. actual clutch pressure in live data.
- Test line pressure and the clutch A pressure control solenoid.
- Inspect for internal leaks or a worn valve body.
- If pressure is fine but the clutch still slips, the clutch is worn and needs service. Clear and re-test.
FAQ
Quick answers
Is it safe to drive with P2857?+
Only gently and briefly. A slipping clutch generates heat that quickly damages it and the fluid. Have it serviced soon.
Can I just clear P2857?+
It returns as soon as the clutch slips again. The pressure or clutch wear cause has to be fixed.
Related codes
Often seen with P2857
Read & clear P2857 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX