Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
The car has a special heater called a glow plug that helps start the engine when it's cold. For cylinder 2, the heater is getting too much power, which can be a problem.
The glow plug control circuit for cylinder 2 is experiencing higher than expected voltage, indicating a potential issue with the circuit or the glow plug itself.
The P066D code indicates that the Engine Control Module (ECM) has detected a high voltage condition in the glow plug control circuit for cylinder 2. This could be due to a short circuit, faulty glow plug, or a problem with the wiring or connectors.
• Difficulty starting the engine in cold weather
• Check Engine Light illuminated
• Reduced engine performance
• Faulty glow plug
• Short circuit in the wiring
• Faulty glow plug control module
Glow Plug: A device used to heat the cylinder in a diesel engine to aid starting.
ECM: Engine Control Module, the computer that controls engine functions.
• Use an OBD-II scanner to confirm the code.
• Inspect the wiring and connectors for cylinder 2 glow plug.
• Test the glow plug for proper resistance.
• Replace the faulty glow plug.
• Repair or replace damaged wiring or connectors.
• Replace the glow plug control module if necessary.
• OBD-II scanner
• Multimeter
• Socket set
$100 - $300
Moderate
• Ford F-250
• Chevrolet Silverado
• Dodge Ram
• Regularly inspect glow plug circuits.
• Perform routine maintenance checks.
• Use high-quality glow plugs.
Sensor Issue
• Have the vehicle inspected by a professional if unsure.
• Avoid driving in extremely cold conditions until fixed.
Check with the vehicle manufacturer for warranty coverage on glow plugs and related components.
Glow plug circuit issues have been common in diesel engines, particularly in cold climates where starting assistance is crucial.
Moderate – It should be addressed soon to avoid starting issues, especially in cold weather.
Ignoring this issue may lead to starting difficulties and reduced engine performance.
• Engine cold start
• Ambient temperature below freezing
The glow plug for cylinder 2 is located in the engine cylinder head, typically near the fuel injector.
Q: Can I drive with a P066D code?
A: It's possible to drive, but you may experience starting issues, especially in cold weather.
Q: How can I prevent glow plug issues?
A: Regular maintenance and using high-quality glow plugs can help prevent issues.
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