P284F
Shift Fork C Unrequested Movement
What it means
P284F means Shift Fork C Unrequested Movement.
Check these first
- A shift fork C that moves without a command
- A leaking shift fork C actuator seal
- A failed shift fork C position sensor
- Debris holding the shift fork C valve open
What to do next
- Read shift fork C position on a scan tool at rest
- Watch for shift fork C movement with no shift commanded
- Command shifts and confirm the shift fork C moves only on command
- Test the shift fork C actuator for a leaking seal
- Replace the shift fork C actuator if it moves uncommanded
- Clear the code and retest
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Updated
Generic SAE J2012 definition. Last updated 2026-10-10.