What does code P2851 mean?

Q: What does code P2851 mean?

Shift Fork Position Sensor A/B Correlation. P2851 means the transmission control module (TCM) has detected a disagreement between the two position sensors that monitor shift fork A and shift fork B inside the transmission. The computer compares the expected fork positions with the actual sensor voltages and sets this code when the correlation between sensor A and sensor B falls outside the calibrated window.

DTC codes / P28xx · Transmission / P2851

P2851Shift Fork Position Sensor A/B Correlation

P2851 means the transmission control module (TCM) has detected a disagreement between the two position sensors that monitor shift fork A and shift fork B inside the transmission. The computer compares the expected fork positions with the actual sensor voltages and sets this code when the correlation between sensor A and sensor B falls outside the calibrated window.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

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.