Technical Description of OBD-II Trouble Code
The range/performance of the glow plug circuit for cylinder 8
What does that signify?
This is a generic diagnostic trouble code (DTC) that applies to OBD-II vehicles, including Ford, Toyota, Dodge, Ram, Chevy, GMC, VW Audi, Peugeot, Citroen, etc. The specific repair steps may vary depending on the year, make, model, and powertrain configuration.
When code P06C0 is stored, it means that the powertrain control module (PCM) has detected an inconsistency in the glow plug control circuit for cylinder #8. Consult a reliable source of vehicle information to determine the location of cylinder #8 for your specific vehicle.
Diesel engines use high compression instead of spark to initiate piston movement. Glow plugs are used in each cylinder to increase cylinder temperature and maximize compression. These glow plugs are different from spark plugs and are threaded into the cylinder head. When voltage is correctly applied to the glow plug, it will glow red hot and aid in increasing cylinder temperature. If the PCM detects a voltage level outside the expected range for the glow plug control circuit of cylinder #8, code P06C0 will be stored and the malfunction indicator lamp (MIL) may illuminate.
Photo of a typical glow plug:
What is the severity of this DTC?
Any glow plug related code will likely cause drivability issues. It is important to address a stored code P06C0 promptly.
What are some of the symptoms of the code?
Symptoms of a P06C0 trouble code may include:
What are some of the common causes of the code?
Possible causes for this P06C0 fuel injector code may include:
What are some P06C0 troubleshooting steps?
To accurately diagnose a code P06C0, you will need a diagnostic scanner, a reliable source of vehicle information, and a digital volt/ohmmeter (DVOM). Use the vehicle information source to search for applicable technical service bulletins (TSB) that match your vehicle make, model, symptoms, and the stored code. This information will help in the diagnosis process.
After visually inspecting all glow plugs and glow plug control wiring and connectors, connect the diagnostic scanner to the vehicle diagnostic port. Retrieve all stored codes and freeze frame data and record them for reference. Test drive the vehicle to see if the code P06C0 is reset. If the code is reset, continue with the diagnosis. If not, you may be dealing with an intermittent condition that requires further worsening for an accurate diagnosis.
A reliable way to test glow plugs is to remove them and apply battery voltage. If the glow plug glows bright red, it is functioning properly. If it fails to heat up, you can test it with a DVOM to check if it meets the manufacturer’s resistance specifications. Be cautious when performing this test to avoid burns or fires.
If the glow plugs appear to be working properly, use the scanner to activate the glow plug timer and test for battery voltage (and a ground) at the glow plug connector using the DVOM. If no voltage is present, test the power supply for the glow plug timer or glow plug controller. Test all related fuses and relays as recommended by the manufacturer. It is best to test system fuses and fusible links with the circuit loaded to avoid diagnostic errors.
If all fuses and relays are functional, use the DVOM to test output voltage at the glow plug timer or PCM. If voltage is detected at the glow plug timer or PCM, there may be an open or shorted circuit. You can investigate the cause of the discrepancy or simply replace the circuit.
