P0678 OBD II Trouble Code Cylinder #8 Glow Plug Circuit DTC

Symptoms of P0678 OBD II Trouble Code

  • The engine management computer (PCM) will set the code P0678
  • The engine will be hard to start or may not start at all in cold weather or when its been sitting long enough for the block to cool.
  • Lack of power until the engine heats up sufficiently.
  • Engine may miss due to the colder than normal cylinder head temperature
  • Engine may hesitate when accelerating
  • No pre-heat period, or in other words the preheat light does not go off.

Common Causes of P0678 OBD II Trouble Code

  • Faulty cylinder #8 glow plug
  • Open or shorted glow plug circuit
  • Damaged wiring connector
  • Faulty glow plug control module