P066B OBD II Trouble Code Cylinder #1 Glow Plug Circuit High

How to easily diagnose, repair, and info on causes of a P066B trouble code that indicates a detected high voltage condition in the glow plug control circuit on cylinder 1.

Symptoms of P066B OBD II Trouble Code

  • Excessive black smoke from exhaust
  • Engine drivability issues
  • Delayed engine start up
  • Reduced fuel efficiency
  • Engine misfire codes may be stored

Common Causes of P066B OBD II Trouble Code

  • Bad glow plug/s
  • Open or shorted glow plug control circuit
  • Loose or faulty glow plug connector
  • Defective glow plug timer

Severity of P066B OBD II Trouble Code

Any glow plug related code will likely be accompanied by drivability issues. A stored code P066B should be addressed with urgency.