P2850
Shift Fork D Unrequested Movement
Shift fork D moves without an actuator command. Hydraulic leakage at the actuator or detent spring failure.
- 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.
- Internal leak in fork actuatorCommon
- Detent spring or ball failedPossible
Parts involved
- Shift Fork D
- Shift Fork Actuator D
- Detent Spring
P2850 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.