Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
The car's computer found a problem with the part that helps spray fuel into the engine. It's like a wire got mixed up with another part, which can cause the car to not run smoothly.
The code indicates that there is a short circuit between the low side of the high-pressure injector for cylinder 3 and the coil, which can disrupt the injector's normal operation.
P31F6 is a diagnostic trouble code indicating a short circuit condition between the low side of the high-pressure fuel injector for cylinder 3 and the ignition coil. This can cause improper fuel delivery to the cylinder, leading to engine performance issues.
• Engine misfire
• Poor fuel economy
• Check Engine Light illuminated
• Damaged wiring harness
• Faulty injector
• Shorted ignition coil
Injector: A device that sprays fuel into the engine's cylinders.
Coil: A component that generates the high voltage needed to ignite the fuel-air mixture in the engine.
• Inspect the wiring harness for damage or wear.
• Test the injector for proper operation.
• Check the ignition coil for shorts.
• Repair or replace damaged wiring.
• Replace the faulty injector.
• Replace the ignition coil if necessary.
• Multimeter
• OBD-II scanner
• Basic hand tools
$200 - $500
Moderate
• Ford F-150
• Chevrolet Silverado
• Toyota Camry
• Regular maintenance checks
• Inspect wiring for wear
• Replace ignition components as needed
Engine Performance
• Avoid driving the vehicle until repaired.
• Consult a professional mechanic for diagnosis.
Check with the vehicle manufacturer for warranty coverage on fuel injectors.
This code has been associated with injector and ignition coil issues in various vehicle models over the years.
High – Can lead to severe engine performance issues if not addressed promptly.
Driving with this code may cause further engine damage and is not recommended.
• Engine running
• Warm operating temperature
The injector is located on the engine, near cylinder 3.
Q: Can I drive with a P31F6 code?
A: It's not recommended as it can cause further engine damage.
Q: What happens if I ignore this code?
A: Ignoring the code can lead to poor engine performance and potential damage.
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Universal · Digital multimeter
A solid entry-level multimeter for voltage, continuity, resistance, and basic electrical troubleshooting.
Helpful for checking voltage drops, grounds, and basic circuit health when modules are not communicating.
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Universal · Wire connectors and repair kit
Useful when diagnosis points toward damaged wiring, corroded terminals, or connector repairs.
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.