Powertrain, generic (extended)

P285B Shift Fork A Actuator Circuit/Open

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P285B covers the electrical drive of the actuator that moves fork A, for designs where an electric motor rather than oil pressure shifts the gears. The module sets it when the output stage sees no load, typically a broken winding, a cut lead or a connector that has backed out. Ford documents the code for the DPS6 dual-clutch box of 2012: shift drum A, which positions the forks for 1st, 3rd and 5th, is turned by a three-phase motor geared 61.44:1 to the drum, and an open motor circuit is logged as P285B. Ford flags it for the MIL. Sibling faults on the same drum are split off: driver chip (P2831), hall sequence (P2835), short to ground (P285D), short to power (P285E) and lost drum position (P2832). Without drum A the odd gears cannot be selected.

Likely causes

Loose, corroded or backed-out connector at the fork A actuator motor
Broken lead between transmission module and actuator motor
Open phase winding inside the actuator motor
Failed motor output stage in the transmission module

Symptoms

  • Malfunction indicator lamp and transmission warning
  • First, third or fifth gear not available, car may only move in the even gears
  • Jerky starts or refusal to pull away

Repair estimate

DifficultyHardWorkshop job
Parts and labour€100–1,500
Time0.5–4 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

shift fork actuator awiring harnesstcm

Related codes

P285CP285DP285EP285FP2831P2832P2835

References: newtonnet.co.uk, performanceparts.ford.com, law.cornell.edu.