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 spray fuel into the engine for cylinder number 4. It's like a broken wire that stops the fuel from getting to where it needs to go.
The code indicates that the electrical circuit responsible for controlling the fuel injector on cylinder 4 is open, meaning there's a break or disconnection.
P3112 is set when the Engine Control Module (ECM) detects an open circuit in the low side of the high-pressure fuel injector for cylinder 4. This can prevent the injector from receiving the necessary electrical signal to operate properly.
• Engine misfire
• Poor fuel economy
• Check Engine Light illuminated
• Broken or damaged wiring harness
• Faulty fuel injector
• Bad connection at the injector or ECM
ECM: Engine Control Module, the computer that controls engine functions.
Injector: A device that sprays fuel into the engine's cylinders.
• Scan the vehicle for codes and note any additional codes.
• Inspect the wiring and connectors for cylinder 4 injector.
• Test the injector resistance and continuity.
• Repair or replace damaged wiring or connectors.
• Replace the faulty fuel injector.
• Clear the codes and test drive to ensure the issue is resolved.
• OBD-II scanner
• Multimeter
• Basic hand tools
$150 - $400
Moderate
• Vehicle 1
• Vehicle 2
• Vehicle 3
• Regular maintenance and inspection of wiring.
• Use high-quality fuel.
• Avoid harsh driving conditions.
Engine Performance
• Do not ignore the Check Engine Light.
• Have the vehicle inspected by a professional if unsure.
• Avoid driving the vehicle if it misfires severely.
Check with the vehicle manufacturer for warranty coverage on emissions-related components.
This code has been associated with injector circuit issues in vehicles with direct fuel injection systems.
Moderate – Addressing this issue promptly can prevent further engine damage.
Ignoring this code can lead to increased emissions and potential engine damage.
• Engine running
• Normal operating temperature
The injector for cylinder 4 is located on the engine, near the intake manifold for the fourth cylinder.
Q: Can I drive with a P3112 code?
A: It's not recommended to drive with this code active, as it can cause engine damage and poor performance.
Q: How can I prevent this code from occurring?
A: Regular maintenance and inspections can help prevent wiring and injector issues.
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Universal · Digital multimeter
A solid entry-level multimeter for voltage, continuity, resistance, and basic electrical troubleshooting.
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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.