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 part of the car that helps inject hydrogen into the engine for cylinder 2. It's like when a squirt gun isn't shooting water properly because something is blocking the trigger.
The P317B code indicates a problem with the electrical circuit that controls the hydrogen injector for cylinder 2. The 'low side' refers to the ground or negative side of the circuit, which is not working properly.
The P317B 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 2. This can be caused by a short to ground, an open circuit, or a faulty injector.
• Check Engine Light is on
• Poor engine performance
• Engine misfires or runs rough
• Faulty hydrogen injector
• Open or shorted wiring in the injector circuit
• Bad connection in the injector circuit
Injector: A device that sprays fuel into the engine's combustion chamber.
Circuit: A path that allows electricity to flow.
• Use an OBD-II scanner to confirm the code
• Inspect the wiring and connectors for cylinder 2 injector
• Test the injector circuit for continuity and shorts
• Repair or replace damaged wiring
• Clean and secure electrical connections
• Replace the hydrogen injector if faulty
• OBD-II scanner
• Multimeter
• Basic hand tools
$150 - $500
Moderate
• Toyota Mirai
• Hyundai Nexo
• Honda Clarity Fuel Cell
• Regular maintenance of fuel system
• Check and secure electrical connections periodically
• Use high-quality fuel
Engine Performance
• Avoid driving the vehicle until repaired to prevent further damage
• Consult a professional mechanic for proper diagnosis and repair
Check with your vehicle manufacturer as some components may be covered under warranty.
This code is relatively new and specific to hydrogen fuel cell vehicles, reflecting the complexity of modern alternative fuel systems.
High – This issue can lead to poor engine performance and potential damage if not addressed promptly.
Driving with an unresolved injector issue can lead to increased emissions and may not comply with local emissions regulations.
• Engine running
• Hydrogen fuel system pressurized
The hydrogen injector for cylinder 2 is located on the engine, typically near the intake manifold.
Q: Can I drive my car with a P317B code?
A: It's not recommended to drive with this code active, as it can lead to engine performance issues and potential damage.
Q: How do I know if my hydrogen injector is faulty?
A: Symptoms include poor engine performance, misfires, and a check engine light. A professional diagnosis is recommended.
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Helpful for checking voltage drops, grounds, and basic circuit health when modules are not communicating.
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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.