01 Important Safety Recall: Ford Recalls 1 Million Vehicles fo… • 02 Can You Change Your Bike's Disc Brake into a Drum Brake? • 03 The World's Biggest and Strongest Ship Engines: A Comprehen… • 04 From Slight Pause to Complete Failure: Understanding Transm… • 05 How to Bleed ABS Module Without a Scan Tool • 06 The Best Oil for Older Diesel Engines: Buyer's Guide • 07 Does Running the AC in Your Car Use More Fuel? • 08 A Comprehensive Guide to Different Types of Automotive Bulbs • 09 What to Do If Your Car Starts and Then Stops • 10 The Consequences of Engaging Reverse Gear While Moving Forw… •

DTC codes / P06xx · Computer and output circuits / P06CC

P06CCCylinder 8 Glow Plug Incorrect

P06CC indicates that the engine control module has detected an incorrect condition for the glow plug assigned to cylinder 8, typically an open circuit, short to ground, or resistance outside the expected range. The module monitors the glow plug circuit during the afterglow phase and sets this code when the feedback signal does not match the commanded state.

SystemPowertrain
Code typeGeneric (all makes)
SeverityLow
Fix difficultyIntermediate
AreaComputer and output circuits

Symptoms you may notice

  • Illuminated check engine light, often with no other noticeable symptoms
  • Hard cold starting or extended cranking before the engine fires
  • Rough idle and white smoke from the exhaust immediately after a cold start
  • Reduced fuel economy during warm-up and increased exhaust emissions
  • In some vehicles, a message on the driver information display indicating a glow plug fault

Common causes, most likely first

  1. Failed glow plug on cylinder 8, typically an open heating element or a burned-out tip
  2. Damaged or corroded electrical connector at the cylinder 8 glow plug
  3. Open or chafed wiring in the glow plug harness between the module and the plug
  4. Faulty glow plug control module that cannot deliver or monitor current to cylinder 8
  5. Poor ground connection for the glow plug circuit or engine block
  6. Moisture intrusion into the glow plug connector or module causing intermittent resistance
  7. Aftermarket glow plug with incorrect resistance specification installed on cylinder 8

How to diagnose and fix it

  1. Clear the code and verify it returns after a cold-start cycle to confirm the fault is current
  2. Inspect the cylinder 8 glow plug connector for corrosion, looseness, or pushed-back terminals
  3. Measure the resistance of the cylinder 8 glow plug with a multimeter and compare it to the manufacturer's specification
  4. Check the glow plug harness for continuity and shorts between the module and the plug
  5. Test the glow plug control module output for cylinder 8 using a bidirectional scan tool or oscilloscope
  6. Replace the faulty glow plug and apply dielectric grease to the connector to prevent moisture intrusion
  7. Verify the repair by performing a cold start and confirming the code does not reset

Why cylinder 8 glow plug codes mislead

  • A glow plug that tests good on a multimeter can still fail under load, so a resistance check alone may miss an intermittent element.
  • The glow plug control module often sets a cylinder-specific code when the actual fault is a shared power or ground circuit affecting multiple cylinders.
  • Carbon buildup on the glow plug tip can alter its resistance and trigger the code without a complete failure of the heating element.
  • Some vehicles require a relearn or adaptation reset after glow plug replacement, and skipping this step can cause the code to return.
  • A weak battery or charging system fault can cause low voltage during afterglow, leading the module to misinterpret the glow plug feedback as incorrect.

Can I keep driving with P06CC?

The vehicle remains safe to drive because the fault primarily affects cold-start performance and emissions, but prolonged driving with a failed glow plug can lead to carbon buildup and harder starting. Avoid heavy loads or extended idling during cold weather until the repair is completed.

Tools that help

Tools we recommend are in the Auto Veteran shop on Amazon. As an Amazon Associate we earn from qualifying purchases.

Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.

Running on fumes Free guides aren't free to make. Top up the tank. Any amount, one time. Fuel the Garage