OBD-II reference

All 9.533 generic OBD-II codes, explained in detail.

Causes, inspection steps and sources — a comprehensive DIY archive. Created and maintained with love for the detail. Good luck and have fun!

Powertrain generic / SAE

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.

SystemPowertrain
Typegeneric / SAE
GroupP2
Range / numberC / F8

Possible causes

  • Bypass actuator mechanically jammed high
  • Control wire shorted to ground medium

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

Inspection / repair

  • Difficulty: hard
  • DIY: shop recommended
  • Estimated cost: 400–1800 €
  • Estimated time: 2–6 h
  • Component: engine coolant bypass valve d
  • Component: ecm
  • MIL / check engine light
  • limp mode possible

Sources

References

How to read OBD-II codes

The first letter names the vehicle system, the second digit distinguishes generic from manufacturer-specific, the remaining digits group fault area and number.

PPowertrain: engine, transmission, emissions
BBody: chassis trim, comfort, interior
CChassis: suspension, brakes, steering
UNetwork: CAN, control modules, communication