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 part of the car that helps start the engine when it's cold isn't working right for the first cylinder. It's like when a light bulb doesn't turn on because there's a problem with the wire.
The P0671 code indicates an issue with the electrical circuit for the glow plug in cylinder 1. Glow plugs are used in diesel engines to help start the engine in cold conditions.
The P0671 code is triggered when the Engine Control Module (ECM) detects an open circuit or a fault in the glow plug circuit of cylinder 1. This could be due to a faulty glow plug, a wiring issue, or a problem with the glow plug control module.
• Difficulty starting the engine in cold weather
• Engine misfire on startup
• Illuminated check engine light
• Faulty glow plug in cylinder 1
• Open or shorted wiring in the glow plug circuit
• Defective glow plug control module
Glow Plug: A device used in diesel engines to preheat the combustion chamber for starting.
ECM: Engine Control Module, the computer that controls engine functions.
• Check the glow plug in cylinder 1 for continuity.
• 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
• Screwdriver set
$100 - $300
Moderate
• Ford F-250
• Chevrolet Silverado
• Dodge Ram 2500
• Regularly inspect glow plugs and wiring.
• Perform routine maintenance checks.
• Use high-quality replacement parts.
Sensor Issue
• Have your vehicle inspected by a professional if the check engine light is on.
• Avoid prolonged engine cranking in cold weather.
• Consider a block heater for extreme cold conditions.
Glow plugs may be covered under powertrain warranty; check with your vehicle manufacturer.
Glow plug circuit issues are common in diesel engines, especially in older models with high mileage.
Moderate – It is advisable to address this issue soon to avoid starting problems, especially in cold weather.
Driving with a faulty glow plug circuit can lead to increased emissions and potential starting issues.
• Engine off and cold
• Battery fully charged
The glow plug for cylinder 1 is located in the engine cylinder head, typically near the fuel injector for that cylinder.
Q: What happens if I ignore the P0671 code?
A: Ignoring the P0671 code can lead to starting difficulties, especially in cold weather, and may cause further engine issues over time.
Q: Can I drive my car with a P0671 code?
A: While you can drive with a P0671 code, it's best to fix it soon to prevent starting problems and potential engine damage.
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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.