Powertrain, generic (extended)

P286A Shift Fork E Unrequested Movement

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P286A flags fork E creeping out of the position that belongs to its current gear, although no shift was requested and no force is being applied. GM uses the code in the 2023 Corvette dual-clutch TCM as the Type A drift fault of rod 5: as long as even clutch speed and output speed confirm the gear the module believes is engaged, the measured rod position must stay inside wide tolerance limits around that gear, and leaving them for a confirmation time sets P286A. The test is blocked if the rod 5 sensor already has an electrical or consistency fault. GM also lists P286A among the triggers of a synchronizer recovery routine. A drifting fork can let a gear partly disengage under load; worn detents, leaking actuation valves and lost references are typical.

Likely causes

Weak detent spring or worn detent notch on the fork E rod
Leaking synchronizer actuation valve pushing the rod
Position reference of rod 5 lost after repair

Symptoms

  • Gear on fork E jumps out or shudders under load
  • Unexpected reshift or brief loss of drive
  • Warning lamp and stored transmission code

Repair estimate

DifficultyHardWorkshop job
Parts and labour€100–3,000
Time1–10 h

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

Parts involved

shift fork eshift fork actuator edetent spring

Related codes

P2869P2864P2850P2868

References: gsi.ext.gm.com, law.cornell.edu.