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 part that controls how much fuel goes into cylinder number 5 in your car's engine. It's like when a light switch is broken and can't turn the light on properly.
The code indicates that the low side circuit of the injector for cylinder 5 is not functioning correctly, likely due to an electrical issue.
The P318E code is triggered when the Engine Control Module (ECM) detects a low voltage condition in the low side circuit of the hydrogen injector for cylinder 5. This could be due to a short circuit, open circuit, or a faulty injector.
• Check Engine Light illuminated
• Engine misfire
• Reduced engine performance
• Faulty injector
• Open or shorted wiring in the injector circuit
• Bad connection in the injector harness
Injector: A device that delivers fuel into the engine's combustion chamber.
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 cylinder 5 injector.
• Test the injector for proper resistance and operation.
• Repair or replace damaged wiring or connectors.
• Replace the faulty injector.
• Clear the code and test drive the vehicle to ensure the issue is resolved.
• OBD-II scanner
• Multimeter
• Basic hand tools
$150 - $400
Moderate
• Toyota Mirai
• Hyundai Nexo
• Honda Clarity Fuel Cell
• Regular maintenance checks
• Ensure proper electrical connections
• Use quality fuel
Engine Performance
• Avoid driving the vehicle until repaired to prevent further damage.
• Consult a professional mechanic for accurate diagnosis.
Check with the vehicle manufacturer for warranty coverage on emission-related components.
This code is relatively new and specific to hydrogen fuel cell vehicles, reflecting the growing adoption of alternative fuel technologies.
Moderate – While the vehicle may still run, performance is compromised and could lead to further damage.
Driving with a malfunctioning injector can lead to increased emissions and potential engine damage.
• Engine running
• Vehicle at operating temperature
The injector for cylinder 5 is located on the engine block, typically on the side or top, depending on the engine layout.
Q: Can I drive with a P318E code?
A: It's not recommended as it can lead to further engine damage and reduced performance.
Q: How can I prevent this code from appearing?
A: Regular maintenance and ensuring good electrical connections can help prevent this issue.
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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.