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 is having trouble measuring the electric signals in the fourth cylinder of the engine. It's like when a flashlight doesn't work because the batteries are too low.
The ion current sense circuit in cylinder 4 is responsible for detecting the electrical charge in the cylinder, which helps monitor combustion. A low reading indicates a problem with this detection.
The P289E code is triggered when the Engine Control Module (ECM) detects that the ion current sense circuit for cylinder 4 is below the expected range. This circuit is used to monitor the combustion process by measuring ionization levels in the cylinder, which can indicate misfires or other combustion issues.
• Check Engine Light (CEL) is on
• Rough engine idle
• Poor fuel economy
• Faulty ignition coil
• Wiring issues in the ion current circuit
• Defective spark plug in cylinder 4
ECM: Engine Control Module
Ionization: The process by which an atom or a molecule acquires a negative or positive charge
• Use an OBD-II scanner to confirm the code.
• Inspect the ignition coil and spark plug for cylinder 4.
• Check the wiring and connectors for damage or corrosion.
• Replace the faulty ignition coil.
• Repair or replace damaged wiring.
• Install a new spark plug in cylinder 4.
• OBD-II scanner
• Multimeter
• Socket set
$150 - $300
Moderate
• Toyota Camry
• Ford F-150
• Honda Accord
• Regularly check and replace spark plugs.
• Inspect ignition coils periodically.
• Maintain clean and secure wiring connections.
Sensor Issue
• Do not ignore the Check Engine Light.
• Have the vehicle inspected by a professional if unsure.
• Regular maintenance can prevent this issue.
Check with your vehicle manufacturer for warranty coverage on ignition components.
This code is relatively uncommon and often associated with specific ignition system issues.
Moderate – While the vehicle may still be drivable, it can lead to more severe engine problems if not addressed.
Driving with a misfire can cause increased emissions and potential engine damage.
• Engine running
• Vehicle at operating temperature
The ion current sense circuit is part of the ignition system, typically located near the ignition coil and spark plug of cylinder 4.
Q: Can I drive with a P289E code?
A: It's possible to drive, but it's not recommended. It can lead to further engine damage.
Q: Will a P289E code cause my car to fail an emissions test?
A: Yes, a misfire can increase emissions and cause a test failure.
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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.