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 is saying there's a problem with the part that sprays fuel into one of the engine's cylinders. It's like when a garden hose is kinked and water can't flow through.
This code indicates that there is an issue with the electrical circuit that controls the fuel injector for cylinder 3. The circuit is either open or experiencing low voltage.
The P317D code is triggered when the Engine Control Module (ECM) detects a fault in the low side circuit of the hydrogen injector for cylinder 3. This could be due to an open circuit or low voltage condition, preventing the injector from operating correctly.
• Check Engine Light is on
• Engine misfire
• Reduced engine performance
• Faulty fuel injector
• Damaged wiring or connectors
• Faulty ECM
ECM: Engine Control Module
Injector: A device that sprays fuel into the engine's cylinders
• Inspect the wiring and connectors for damage.
• Test the injector for proper operation.
• Check the ECM for faults.
• Repair or replace damaged wiring or connectors.
• Replace the faulty injector.
• Reprogram or replace the ECM if necessary.
• OBD-II scanner
• Multimeter
• Fuel injector tester
$150 - $500
Moderate
• Toyota Mirai
• Hyundai Nexo
• Honda Clarity Fuel Cell
• Regular maintenance checks
• Ensure fuel quality
• Inspect wiring regularly
Engine Performance
• Do not ignore the Check Engine Light.
• Get the vehicle inspected by a professional.
• Avoid driving the vehicle aggressively until fixed.
Check with your vehicle manufacturer for warranty coverage on fuel injectors and related components.
This code is relatively uncommon and specific to hydrogen fuel cell vehicles, reflecting the complexity of their fuel injection systems.
Moderate – Should be addressed soon to prevent further engine damage.
Driving with a faulty injector can lead to increased emissions and potential engine damage.
• Engine at operating temperature
• Vehicle stationary
The hydrogen injector for cylinder 3 is located on the engine, near the intake manifold.
Q: Can I drive with a P317D code?
A: It's not recommended to drive for long periods with this code active, as it can lead to engine damage.
Q: How do I reset the Check Engine Light after fixing the issue?
A: Use an OBD-II scanner to clear the code after repairs are completed.
High-End · Full-system diagnostics
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Network faults often require full-system access instead of a generic code reader alone.
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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.