Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
This code means there's a problem with the electrical circuit that controls the fuel injector for cylinder 10 in your car's engine. It's like a broken wire or a switch that isn't working right.
The P31D2 code indicates that the high side circuit for the high-pressure fuel injector on cylinder 10 is experiencing low voltage or an open circuit.
The high-pressure injector for cylinder 10 is controlled by an electrical circuit. This circuit is responsible for providing the necessary voltage to operate the injector. If the circuit is experiencing low voltage or an open condition, the injector may not function correctly, leading to performance issues.
• Engine misfire
• Poor fuel economy
• Check engine light on
• Faulty injector
• Damaged wiring or connectors
• Faulty engine control module (ECM)
Injector: A device that sprays fuel into the engine's cylinders.
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 damage.
• Test the injector and circuit for proper voltage.
• Repair or replace damaged wiring or connectors.
• Replace the faulty injector.
• Replace or reprogram the ECM if necessary.
• OBD-II scanner
• Multimeter
• Basic hand tools
$200 - $800
Moderate
• Vehicle 1
• Vehicle 2
• Vehicle 3
• Regular maintenance checks
• Ensure proper fuel quality
• Inspect wiring periodically
Engine Performance
• Do not ignore the check engine light.
• Seek professional diagnostic service.
• Avoid driving with a misfiring engine.
Check your vehicle's warranty for coverage on engine components.
This code is relatively rare and typically associated with high-performance or large engines with multiple cylinders.
Moderate – Should be addressed soon to avoid further engine damage.
Driving with a misfiring engine can lead to increased emissions and potential safety hazards.
• Engine running
• Warm engine temperature
The injector is located on the engine block, specifically on cylinder 10.
Q: Can I drive with a P31D2 code?
A: It's not recommended to drive with this code as it can lead to more severe engine damage.
Q: How do I clear the P31D2 code?
A: After repairs, use an OBD-II scanner to clear the code from the ECM.
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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.