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 computer in the car is having trouble controlling the little heater (glow plug) in the first cylinder of the engine. It's like when a toaster doesn't heat up properly.
The P066A code indicates that the engine control module (ECM) has detected a low voltage condition in the glow plug control circuit for cylinder 1.
The glow plug control circuit is responsible for providing the necessary voltage to the glow plug in cylinder 1. This plug helps in warming up the engine for better starting performance, especially in cold conditions. A low circuit condition usually means there's an issue with the wiring, connectors, or the glow plug itself, causing insufficient voltage to reach the glow plug.
• Hard starting, especially in cold weather
• Rough idle
• Check Engine Light illuminated
• Faulty glow plug
• Wiring issues in the glow plug circuit
• Faulty glow plug control module
Glow Plug: A device used to heat the cylinder in a diesel engine to aid in starting.
ECM: Engine Control Module, the computer that controls engine functions.
• Check for any blown fuses related to the glow plug circuit.
• Inspect the wiring and connectors for damage or corrosion.
• Test the glow plug for proper resistance and operation.
• Replace the faulty glow plug.
• Repair or replace damaged wiring or connectors.
• Replace the glow plug control module if necessary.
• Multimeter
• OBD-II scanner
• Basic hand tools
$100 - $300
Moderate
• Ford F-250
• Chevrolet Silverado
• Dodge Ram
• Regularly inspect glow plug connections.
• Perform routine maintenance on the vehicle's electrical system.
• Use high-quality glow plugs.
Sensor Issue
• Have the vehicle inspected by a professional if you experience hard starting.
• Avoid driving in extremely cold conditions until the issue is resolved.
Check with the vehicle manufacturer for specific warranty coverage on glow plugs and related components.
Glow plug issues are common in diesel engines, especially in older models or those in cold climates.
Moderate – While it may not cause immediate damage, it can lead to hard starting and should be addressed soon.
Driving with a faulty glow plug can lead to increased emissions and may not comply with local emissions regulations.
• Engine should be cold.
• Ambient temperature should be considered as it affects glow plug operation.
The glow plug for cylinder 1 is located on the engine block, near the first cylinder, which is typically at the front of the engine.
Q: Can I drive with a P066A code?
A: It's best to address the issue soon, as it can lead to hard starting and increased emissions.
Q: How do I know if my glow plug is bad?
A: Symptoms include hard starting, rough idle, and the Check Engine Light being on.
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