Powertrain Definition only Lights the check engine lamp

P285F: Shift Fork B Actuator Circuit/Open

Standardized SAE J2012 code · P28xx codes

What does P285F mean?

The control circuit for shift fork B actuator reports a actuator circuit/open condition. Fork engagement cannot be commanded reliably.

The code tells you which monitor failed, not which part is broken. Test before replacing parts.

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

  • High Open in actuator control wire
  • Medium Open actuator coil
  • Low Pin pushed back out of connector body

Likelihood is a general estimate across vehicles; your make and model may differ.

Add your car to see reports of P285F on the same make and model first.

P285F in the community

Ask about P285F

No one has posted about P285F yet

Share your vehicle, the tool you used and what you tested — the first thread helps everyone who searches for this code.

Describe your P285F problem