Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
This code means that the car's computer has detected a problem with the electrical circuit that heats up the glow plug in the 12th cylinder of a diesel engine. Glow plugs are like little heaters that help the engine start when it's cold.
The P0682 code indicates an issue with the electrical circuit responsible for powering the glow plug in cylinder 12. This can affect the engine's ability to start, especially in cold conditions.
The P0682 code is set when the Engine Control Module (ECM) detects an open circuit or a fault in the glow plug circuit for cylinder 12. This could be due to a faulty glow plug, wiring issues, or a problem with the glow plug control module.
• Difficulty starting the engine, especially in cold weather
• Engine misfires
• Check Engine Light illuminated
• Faulty glow plug in cylinder 12
• Damaged or corroded wiring or connectors
• Faulty glow plug control module
Glow Plug: A device used to heat the air in a diesel engine cylinder to aid starting.
ECM: Engine Control Module, the computer that controls the engine's operation.
• Use an OBD-II scanner to confirm the code.
• Inspect the wiring and connectors for cylinder 12's glow plug.
• Test the glow plug for proper resistance and operation.
• Replace the faulty glow plug in cylinder 12.
• Repair or replace damaged wiring or connectors.
• Replace the glow plug control module if necessary.
• OBD-II scanner
• Multimeter
• Socket set
$150 - $300
Moderate
• Ford F-250 Super Duty
• Chevrolet Silverado 2500HD
• Ram 2500
• Regularly inspect and maintain the glow plug system.
• Ensure connectors and wiring are clean and secure.
• Use high-quality glow plugs.
Engine Performance
• Have the glow plug system inspected regularly.
• Address Check Engine Light warnings promptly.
Glow plugs may be covered under the vehicle's powertrain warranty. Check with the manufacturer.
Glow plug circuit issues have been common in diesel engines, especially in older models or those frequently used in cold climates.
Moderate – It should be addressed to ensure reliable engine starting, especially in cold weather.
Driving with a faulty glow plug circuit can lead to starting issues and increased emissions.
• Engine cold start
• Ambient temperature below 50°F
The glow plug for cylinder 12 is located on the engine's cylinder head, typically near the intake manifold.
Q: Can I drive with a P0682 code?
A: You can drive, but starting the engine may be difficult, especially in cold weather. It's best to address the issue soon.
Q: How do glow plugs work?
A: Glow plugs heat the air in a diesel engine's cylinders to help the engine start in cold conditions.
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Useful if diagnosis points toward damaged connectors, wiring, or terminal repairs.
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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.