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 noticing that the part that makes the spark for the engine isn't working right. It's like trying to light a candle with a wet match.
The ignition coil is responsible for converting the battery's voltage to a higher voltage to create a spark in the spark plugs. This code indicates that the voltage in the ignition coil 'A' is lower than expected.
The P1366 code is triggered when the Powertrain Control Module (PCM) detects a low voltage condition in the primary or secondary circuit of ignition coil 'A'. This can affect the engine's ability to start and run efficiently.
• Engine misfires
• Rough idling
• Difficulty starting the engine
• Faulty ignition coil
• Wiring issues in the ignition coil circuit
• Malfunctioning PCM
PCM: Powertrain Control Module, the computer that controls engine functions.
Ignition Coil: A component that converts battery voltage to a higher voltage to create a spark in the spark plugs.
• Use an OBD-II scanner to confirm the code.
• Inspect the ignition coil and its wiring for damage.
• Check the voltage and resistance of the ignition coil.
• Replace the faulty ignition coil.
• 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 coils and wiring.
• Perform routine maintenance checks.
• Use high-quality fuel.
Engine Performance
• Get the vehicle inspected by a professional mechanic.
• Avoid driving the vehicle until the issue is resolved to prevent further damage.
Check if the ignition system components are covered under the vehicle's warranty.
This code has been commonly reported in vehicles with aging ignition systems or those with known electrical issues.
Moderate – Should be addressed soon to avoid potential engine damage.
Driving with this code can lead to increased emissions and may not meet legal emission standards.
• Engine running
• Vehicle in park or neutral
The ignition coil is typically located on top of the engine, near the spark plugs.
Q: Can I drive with a P1366 code?
A: It's not recommended to drive with this code as it can cause engine performance issues and potential damage.
Q: How do I clear a P1366 code?
A: After repairs, use an OBD-II scanner to clear the code. If the issue is resolved, it should not return.
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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.