What does code P2859 mean?

Q: What does code P2859 mean?

Clutch A Pressure Disengagement Performance/Too Low. P2859 indicates that the transmission control module (TCM) has detected a hydraulic or mechanical fault in clutch A's pressure disengagement circuit, where the clutch is not releasing pressure as commanded. The computer compares expected clutch pressure behavior against actual sensor feedback and sets this code when disengagement pressure falls below the calibrated threshold.

DTC codes / P28xx · Transmission / P2859

P2859Clutch A Pressure Disengagement Performance/Too Low

P2859 indicates that the transmission control module (TCM) has detected a hydraulic or mechanical fault in clutch A's pressure disengagement circuit, where the clutch is not releasing pressure as commanded. The computer compares expected clutch pressure behavior against actual sensor feedback and sets this code when disengagement pressure falls below the calibrated threshold.

SystemPowertrain

Code typeGeneric (all makes)

SeverityHigh

Fix difficultyProfessional

AreaTransmission

Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.