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 there's a problem with the fuel injector for cylinder number 10 in your car's engine. It's like a tiny hose that sprays fuel into the engine, and something is wrong with its wiring.
The code indicates an electrical issue with the fuel injector for cylinder 10, specifically a short circuit between the low side of the injector and the coil.
The P31FD code is triggered when the Engine Control Module (ECM) detects a short circuit between the low side of the high-pressure fuel injector for cylinder 10 and the coil. This can result in improper fuel delivery to the cylinder, affecting engine performance.
• Engine misfire
• Reduced engine performance
• Check Engine Light illuminated
• Damaged or frayed wiring to the injector
• Faulty injector coil
• Short circuit in the injector harness
Injector: A device that sprays fuel into the engine's combustion chamber.
ECM: Engine Control Module, the computer that controls engine functions.
• Inspect the wiring and connectors for cylinder 10 injector.
• Check the injector coil for continuity and resistance.
• Use a multimeter to test for a short circuit in the harness.
• Repair or replace damaged wiring.
• Replace the faulty injector.
• Fix any short circuits in the harness.
• Multimeter
• OBD-II scanner
• Basic hand tools
$150 - $500
Moderate
• BMW 7 Series
• Mercedes-Benz S-Class
• Audi A8
• Regularly inspect engine wiring for damage.
• Use high-quality fuel to prevent injector clogging.
• Perform routine engine maintenance.
Engine Performance
• Avoid driving the vehicle until repairs are made.
• Consult a professional mechanic for diagnosis and repair.
Check your vehicle's warranty for coverage on fuel injector issues.
This code is relatively uncommon and typically occurs in high-performance engines with complex fuel systems.
High – This issue can lead to engine damage if not addressed promptly.
Driving with a malfunctioning injector can lead to increased emissions and potential safety hazards.
• Engine at operating temperature
• Vehicle in idle or under load
The fuel injector for cylinder 10 is located on the engine block, typically near the intake manifold.
Q: Can I drive with code P31FD?
A: It's not recommended to drive with this code as it can cause engine damage.
Q: How do I clear the P31FD code?
A: After repairs, use an OBD-II scanner to clear the code, but ensure the issue is fixed first.
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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.