What Does P06C0 Mean?
The glow plug circuit for cylinder 8 is operating outside its expected performance range. On V8 diesel engines, cylinder 8 is typically the rearmost cylinder on one bank. The glow plug is not reaching the required temperature within the expected time, reducing cold combustion assistance for that cylinder. The driver may experience extended cranking times and rough cold idle.
Common Causes
40%
Cylinder 8 glow plug element degraded with resistance outside specification
25%
High-resistance electrical connection at the cylinder 8 glow plug due to heat and vibration at the rear of the engine
15%
Glow plug control module fault affecting cylinder 8 output
10%
Incorrect glow plug installed during previous service
10%
ECM receiving incorrect temperature sensor data affecting glow plug duration for all cylinders
Diagnostic Steps
1
Measure the cylinder 8 glow plug resistance and compare to specification and the other seven cylinders.
2
Perform a glow plug current draw test on all eight cylinders simultaneously — identify if cylinder 8 draws significantly less current.
3
Inspect the bus bar and connection at cylinder 8 — the rearmost position is most susceptible to heat damage and corrosion.
4
Check the glow plug control module output at the cylinder 8 terminal during preheat to verify proper voltage and duty cycle.
5
If replacement is needed, consider replacing all glow plugs on the same bank as preventive maintenance if the engine has high mileage.
Estimated Repair Cost
$100 - $700
Parts + labor, varies by vehicle and location
The glow plug circuit for cylinder 8 is operating outside its expected performance range. On V8 diesel engines, cylinder 8 is typically the rearmost cylinder on one bank. The glow plug is not reaching the required temperature within the expected time, reducing cold combustion assistance for that cyl...
The most common cause of P06C0 (Cylinder 8 Glow Plug Circuit Range/Performance) is: Cylinder 8 glow plug element degraded with resistance outside specification
Typical repair costs for P06C0 range from $100 to $700, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Safe to drive once the engine reaches operating temperature. Cold starts will be progressively harder in cold weather. Repair before winter for reliable diesel cold starting. If multiple cylinders show glow plug faults, all should be replaced as a set.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P06C0 to identify the root cause.
OBDHut Mobile App
Scan codes directly from your car with the OBDHut app.
Coming Soon
Quick Info
Category
Powertrain
System
Diesel Cold Start / Glow Plug System
Difficulty
Type
Generic (SAE)
Recommended Tools
OBD2 Scanner
A quality scan tool helps you read codes, view live data, and clear faults.
