Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
This means that the car's computer has detected a problem with the part that helps heat up one of the engine's cylinders, specifically cylinder number 7, to make it start better when it's cold.
The glow plug control circuit for cylinder 7 is not functioning properly, indicating a low voltage condition.
The P068C code is triggered when the Engine Control Module (ECM) detects a low voltage condition in the glow plug control circuit for cylinder 7. Glow plugs are used in diesel engines to preheat the combustion chamber, allowing for easier starting in cold conditions. A low voltage condition may indicate a problem with the glow plug itself, the wiring, or the control module.
• Hard starting in cold weather
• Engine misfire
• Illuminated check engine light
• Faulty glow plug
• Damaged wiring or connectors
• Faulty glow plug control module
Glow Plug: A device used in diesel engines to preheat the air in the combustion chamber.
ECM: Engine Control Module, the computer that controls engine functions.
• Check the glow plug for cylinder 7 for proper resistance.
• Inspect the wiring and connectors for damage or corrosion.
• Test the glow plug control module for proper operation.
• Replace the faulty glow plug.
• Repair or replace damaged wiring or connectors.
• Replace the glow plug control module if necessary.
• Multimeter
• Socket set
• Diagnostic scanner
$150 - $400
Moderate
• Ford F-250
• Chevrolet Silverado 2500
• Dodge Ram 2500
• Regularly inspect glow plugs and wiring.
• Use high-quality diesel fuel.
• Schedule regular maintenance checks.
Engine Performance
• Have your vehicle inspected by a professional if you experience hard starting.
• Avoid driving in extremely cold conditions until the issue is fixed.
Check your vehicle's warranty for coverage on engine components.
Glow plug issues are common in diesel engines, particularly in colder climates where they are used frequently.
Moderate – Addressing this issue is important to ensure reliable starting in cold weather.
Driving with a faulty glow plug can lead to increased emissions and potential engine damage.
• Cold engine start
• Ambient temperature below 40°F
The glow plug for cylinder 7 is located on the engine block, typically on the passenger side in a V8 engine configuration.
Q: Can I drive with a P068C code?
A: While you can drive with this code, it is advisable to get it fixed to avoid starting issues, especially in cold weather.
Q: How do glow plugs work?
A: Glow plugs heat up the air in the diesel engine's cylinders to help the fuel ignite more easily, especially in cold conditions.
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Fitment Required · Vehicle-fitment part
Commonly relevant for misfire, ignition-efficiency, and some drivability-related repairs.
Misfire and ignition-related faults commonly involve spark plugs as part of the repair path.
Check the correct plug type, gap, and engine application for your vehicle.
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Fitment Required · Vehicle-fitment part
Relevant when the fault points toward ignition-coil performance or cylinder-specific ignition issues.
Some ignition faults involve coil performance or cylinder-specific coil problems.
Match the coil to your engine and confirm the failed component before ordering.
View options on AmazonThese parts may be related to this fault category, but a code by itself does not confirm exact fitment or guarantee that replacing a part will solve the problem.