P2859Clutch A Pressure Disengagement 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
- P2859 concerns the release side of clutch A: during a ratio change the control unit sees that the pressure handover is not working as planned, so the old and new power paths overlap or the wrong ratio persists. Mitsubishi's Mirage CVT shows how this is tested. With the first auxiliary ratio commanded, a fault is logged when the ratio stays within 10 % of the second ratio (0.900–1.100) for 0.5 s, if it leaves the plausible window (0.911 or less, 2.732 or more) for 0.2 s, or if the high clutch pressure switch reads on for 1.5 s at up to 10 km/h while its target pressure is zero. Nissan lists P2859 among the Kicks/Versa CVT pressure codes, and Mercedes-Benz calls it a general malfunction of multidisk clutch 1 on the 8G-DCT. Harsh or doubled shifts follow.
- What you may notice
- Harsh, doubled or tied-up shifts
- Wrong gear stage held, engine speed too low or too high
- Transmission warning and emergency program
- Likely causes
- LikelyOutgoing clutch not venting in time, so both elements carry torque
- PossibleSticking pressure control solenoid or valve in the valve body
- RareClutch pressure switch reporting pressure that is not there
- 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.