OBD-II code · Powertrain (generic, extended)

P28EF Engine Disconnect Clutch Actuator Performance/Stuck Off

The engine disconnect clutch actuator is commanded to engage but does not produce the expected motion. Actuator stuck in disengaged position.

Is it safe to drive with P28EF?

The car may go into limp mode (reduced power). Get it diagnosed before a long trip.

Common causes

  • Most likelyActuator mechanically stuck off
  • PossibleHydraulic engagement pressure lost
  • Less likelyCarbon or debris buildup preventing free movement

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

Repair at a glance

Difficulty
Hard
DIY friendly
Best left to a mechanic
Typical labour
2–9 h
Emissions test
Usually unaffected
Parts involved
Engine Disconnect Clutch Actuator, Hybrid Control Module

Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.