P066B - OBD II Trouble Code

Our automotive experts have put together the following information about the P066B diagnostic trouble code. We've provided the common symptoms that occur when this code is set along with the frequent repairs that address the issues related to the P066B code.

OBD II Fault Code

• OBD II P066B

OBD-II Code Hard or no start in cold weather is defined as a Cylinder 1 Glow Plug Control Circuit High

The Glow Plug is used on diesel engines to preheat the cylinder before the engine is started. If the engine control module (PCM) detects the glow plug for cylinder one is not operating properly, the PCM will set code P066A.

Hard or no start in cold weather Symptoms

• Engine may not start
• Hard or no start in cold weather

Common Problems That Trigger the P066B Code

• Glow plug control module failure
• Glow plug failure
• Glow plug relay failure
• Glow plug wiring harness failure

Common Repairs Needed for the P066B Code

• Glow Plug Replacement