Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
This code means that the car's computer detected a problem with the way it senses the electric current in cylinder 4 of the engine. It's like the computer is trying to listen to a specific sound, but the sound is too loud.
The ion current sensing circuit is used to detect misfires and other combustion-related issues by measuring the ionization current in the combustion chamber. A 'high' circuit condition indicates an abnormally high voltage or current reading.
The P289F code is triggered when the Engine Control Module (ECM) detects a high voltage or current condition in the ion current sensing circuit of cylinder 4. This circuit is part of the ignition system and is used to monitor combustion quality by measuring ionization levels. An abnormal reading can indicate issues with the ignition coil, wiring, or the ECM itself.
• Check Engine Light is on
• Engine misfires
• Rough engine idle
• Faulty ignition coil in cylinder 4
• Damaged or corroded wiring/connectors
• Faulty Engine Control Module (ECM)
ECM: Engine Control Module
Ionization: A process where atoms or molecules gain or lose electrons, often used in combustion monitoring.
• Use an OBD-II scanner to confirm the code.
• Inspect the ignition coil and wiring for cylinder 4.
• Test the ion current sensor circuit for proper voltage and resistance.
• Replace the ignition coil for cylinder 4.
• Repair or replace damaged wiring/connectors.
• Reprogram or replace the ECM if necessary.
• OBD-II scanner
• Multimeter
• Basic hand tools
$150 - $500
Moderate
• Ford F-150
• Chevrolet Silverado
• Toyota Camry
• Regular maintenance of ignition components
• Keep electrical connections clean and secure
• Use high-quality fuel
Sensor Issue
• Avoid driving the vehicle until the issue is diagnosed.
• Consult a professional mechanic for accurate diagnosis.
Check with the vehicle manufacturer for warranty coverage on ignition system components.
This code has been associated with ignition coil failures and wiring issues in various vehicle models.
Moderate – It should be addressed soon to prevent further engine performance issues.
Ignoring this code can lead to increased emissions and potential engine damage.
• Engine at operating temperature
• Vehicle in park or neutral
The ignition coil and ion current sensor for cylinder 4 are located on the engine's cylinder head, typically near the spark plug.
Q: Can I drive with a P289F 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 can I prevent this code from occurring?
A: Regular maintenance of the ignition system and ensuring all electrical connections are clean and secure can help prevent this issue.
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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.