OBD-II code · Powertrain (generic, extended)

P2CF8 Engine Coolant Bypass Valve D Control Circuit Driver Current/Temperature Too High

The output driver for the engine coolant bypass valve D actuator reports current or junction temperature above its protection threshold. Stalled actuator or short to ground.

Is it safe to drive with P2CF8?

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

Common causes

  • Most likelyBypass actuator mechanically jammed
  • PossibleControl wire shorted to ground

Symptoms

  • Check engine light on
  • Cooling fan runs constantly or not at all
  • Cabin heater weak or excessively hot
  • Possible long warm-up time or hard cold start

Repair at a glance

Difficulty
Hard
DIY friendly
Best left to a mechanic
Typical labour
2–6 h
Emissions test
Usually unaffected
Parts involved
Engine Coolant Bypass Valve D, Ecm

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