Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
This means that the computer in your car has detected a problem with the electrical circuit that controls the injector for cylinder 12. It's like when a light switch doesn't work because the wire is broken.
The P31AF code indicates that the engine control module (ECM) has detected a low voltage condition in the low side circuit of the hydrogen injector for cylinder 12.
The P31AF code is set when the ECM detects a lower than expected voltage in the low side circuit of the hydrogen injector for cylinder 12. This could be due to a short to ground, an open circuit, or a faulty injector. The low side circuit is responsible for completing the electrical path to ground, allowing the injector to function properly.
• Check engine light is on
• Poor engine performance
• Increased emissions
• Faulty hydrogen injector for cylinder 12
• Open or shorted injector circuit
• Faulty ECM
ECM: Engine Control Module
Injector: A device that sprays fuel into the engine's cylinders
• Check for any additional codes and address them first.
• Inspect the injector wiring and connectors for damage.
• Test the injector resistance and compare it to specifications.
• Repair or replace damaged wiring or connectors.
• Replace the faulty hydrogen injector.
• Replace or reprogram the ECM if necessary.
• OBD-II scanner
• Digital multimeter
• Injector tester
$200 - $800
Moderate
• Vehicle 1
• Vehicle 2
• Vehicle 3
• Regularly inspect and maintain injector wiring.
• Use high-quality fuel to prevent injector clogging.
• Perform regular engine diagnostics.
Engine Performance
• Avoid driving the vehicle until repaired to prevent further damage.
• Consult a professional mechanic for accurate diagnosis.
Check with your vehicle manufacturer for warranty coverage on injectors and ECM.
This code is relatively rare and specific to vehicles equipped with hydrogen fuel systems.
Moderate – Address the issue soon to avoid potential engine damage.
Driving with a faulty injector can lead to increased emissions and potential engine damage.
• Engine at operating temperature
• Vehicle in a safe, stationary position
The hydrogen injector for cylinder 12 is located on the engine, typically near the intake manifold.
Q: Can I drive with a P31AF code?
A: It's not recommended to drive with this code as it can lead to engine performance issues.
Q: How do I clear a P31AF code?
A: After repairs, use an OBD-II scanner to clear the code. If the issue persists, the code will return.
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