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 not getting enough power to control the fuel injectors on one side of the engine.
The Engine Control Module (ECM) is detecting a low voltage condition in the power supply to the high-pressure fuel injectors on bank 1 of the engine.
The P31E2 code indicates that the ECM has detected a voltage level lower than expected in the circuit supplying power to the high-pressure injectors on bank 1. This low voltage can affect the injector's performance, leading to improper fuel delivery.
• Engine misfires
• Poor fuel economy
• Check Engine Light illuminated
• Faulty ECM
• Wiring issues such as a short or open circuit
• Failed injector driver circuit
ECM: Engine Control Module
Injector: A device that sprays fuel into the engine's cylinders
• Check the battery voltage and charging system.
• Inspect the wiring and connectors for damage or corrosion.
• Test the injector driver circuit for continuity and proper voltage.
• Repair or replace damaged wiring or connectors.
• Replace the ECM if it is faulty.
• Ensure the battery and charging system are functioning correctly.
• Multimeter
• OBD-II scanner
• Basic hand tools
$200 - $1000
Moderate
• Toyota Camry
• Honda Accord
• Ford F-150
• Regularly inspect and maintain electrical connections.
• Ensure battery and charging system are in good condition.
• Avoid aftermarket modifications that could affect electrical systems.
Engine Performance
• Have the vehicle inspected by a professional mechanic.
• Avoid driving the vehicle if it exhibits severe symptoms.
• Regular maintenance can prevent similar issues.
Check with the vehicle manufacturer for specific warranty coverage related to ECM and injector components.
This code has been associated with issues in vehicles using direct fuel injection systems, where precise control of injector operation is crucial.
Moderate – Addressing this issue promptly can prevent further engine performance problems.
Driving with a malfunctioning injector system can lead to increased emissions and potential safety hazards.
• Engine running
• Battery fully charged
The high-pressure injectors are located on the engine's bank 1, typically on the side where cylinder 1 is located.
Q: Can I drive with a P31E2 code?
A: It's not recommended as it can lead to poor engine performance and increased emissions.
Q: What happens if I ignore this code?
A: Ignoring this code can lead to further engine damage and decreased fuel efficiency.
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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.