P2857
Clutch A Pressure Engagement Performance/Too Low
Clutch A engagement pressure is below the calibrated minimum. Slip during launch and torque transfer reduced.
- Check engine light: Yes
- Emissions related: No
- Repair difficulty: hard
Symptoms
- Check engine or transmission warning light on
- Harsh, delayed, or missing shifts
- Possible limp mode (locked in one gear)
- Slipping or shuddering during gear changes
Common causes
Ordered by how often each turns out to be the cause.
- Hydraulic pump output pressure lowCommon
- Pressure regulator characteristic driftPossible
Parts involved
- Clutch A
- Clutch Actuator A
- Transmission Pump
P2857 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.