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 detected an unusual noise or vibration from cylinder 12, which could mean something is wrong with how the engine is running.
The engine control module (ECM) has detected that the vibration or knock sensor for cylinder 12 is reading a value above the expected threshold, indicating possible engine knocking or abnormal combustion.
The knock sensor monitors the engine for vibrations caused by knocking, which is an uncontrolled explosion in the engine's cylinder. This code indicates that cylinder 12 is experiencing more vibration than normal, which could be due to pre-ignition or detonation. The ECM uses this information to adjust the engine's timing to prevent damage.
• Check Engine Light is on
• Reduced engine performance
• Engine knocking noise
• Poor fuel economy
• Faulty knock sensor
• Poor quality fuel
• Engine timing issues
• Carbon buildup in the cylinder
• Faulty ignition system components
Knock Sensor: A device that detects engine knocking and sends signals to the ECM.
ECM: Engine Control Module, the computer that controls engine functions.
• Use an OBD-II scanner to confirm the code.
• Inspect the knock sensor and its wiring for damage.
• Check for carbon buildup in cylinder 12.
• Test the ignition system for faults.
• Replace the knock sensor if faulty.
• Clean carbon deposits from the engine.
• Repair or replace damaged wiring.
• Adjust engine timing if necessary.
• OBD-II scanner
• Multimeter
• Wrench set
• Carbon cleaner
$150 - $500
Moderate
• High-performance vehicles
• Luxury cars with V12 engines
• Older vehicles with high mileage
• Use high-quality fuel.
• Regularly maintain the engine.
• Ensure timely ignition system servicing.
Engine Performance
• Avoid hard acceleration until the issue is resolved.
• Use premium fuel if recommended by the manufacturer.
Check with your vehicle manufacturer; knock sensors may be covered under the powertrain warranty.
This code is more common in vehicles with high cylinder counts and can be indicative of engine wear or poor fuel quality.
Moderate – Addressing this issue promptly can prevent engine damage.
Ignoring engine knock can lead to severe engine damage and increased emissions.
• Engine at operating temperature
• Under load conditions
The knock sensor is typically located on the engine block, cylinder head, or intake manifold.
Q: Can I drive with a P2347 code?
A: It's not recommended to drive for extended periods with this code, as it can lead to engine damage.
Q: Will using better fuel fix the problem?
A: Using higher-octane fuel may help if the issue is related to fuel quality, but it's best to diagnose the root cause.
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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.