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 has detected a problem with the electrical circuit that controls one of the ignition coils. It's like a switch that is stuck in the 'on' position.
The P2304 code is triggered when the Powertrain Control Module (PCM) detects a high voltage condition in the primary control circuit of ignition coil B.
The ignition coil B primary control circuit is responsible for providing the necessary voltage to ignite the air/fuel mixture in the engine's cylinders. A 'high' condition indicates that the circuit is receiving more voltage than expected, which could lead to misfires or other ignition problems.
• Check Engine Light is on
• Engine misfires
• Poor engine performance
• Faulty ignition coil B
• Wiring issues such as shorts or open circuits
• Defective PCM
PCM: Powertrain Control Module
OBD-II: On-Board Diagnostics, Second Generation
• Use an OBD-II scanner to confirm the code.
• Inspect the ignition coil B and its wiring for damage.
• Test the voltage at the ignition coil connector.
• Replace the faulty ignition coil B.
• Repair or replace damaged wiring.
• Reprogram or replace the PCM if necessary.
• OBD-II scanner
• Multimeter
• Socket set
$100 - $300
Moderate
• Ford F-150
• Chevrolet Silverado
• Toyota Camry
• Regularly inspect ignition system components.
• Ensure proper electrical connections.
• Use quality replacement parts.
Engine Performance
• Don't ignore the Check Engine Light.
• Have the vehicle inspected by a professional if unsure.
• Regular maintenance can prevent such issues.
Check with your vehicle manufacturer for warranty coverage on ignition components.
This code has been known to appear in vehicles with aging ignition systems or after improper repairs.
Moderate – While the vehicle may still be drivable, it can lead to increased fuel consumption and further engine damage if not addressed.
Ignoring this code could lead to increased emissions and potential safety issues due to engine misfires.
• Engine running
• Electrical load applied
The ignition coil is typically located on top of the engine, near the spark plugs.
Q: Can I drive with a P2304 code?
A: It's possible, but not recommended as it can lead to further engine damage.
Q: How do I know if my ignition coil is bad?
A: Symptoms include engine misfires, rough idling, and poor acceleration.
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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.