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 has turned off the spark plug for cylinder 12 because it got too hot or isn't getting a signal.
This code indicates that the ignition coil for cylinder 12 is either overheating or not receiving the necessary signal to function properly.
The Engine Control Module (ECM) has detected an overtemperature condition or a lack of signal from the ignition coil associated with cylinder 12. This may result in the ECM disabling the coil to prevent damage.
• Engine misfire
• Reduced engine performance
• Check Engine Light illuminated
• Faulty ignition coil
• Wiring issues or poor connections
• ECM malfunction
ECM: Engine Control Module
Ignition Coil: A component that transforms the battery's voltage to a higher voltage to ignite the fuel.
• Inspect ignition coil for damage or overheating.
• Check wiring and connections to the ignition coil.
• Test the ignition coil with a multimeter.
• Replace the faulty ignition coil.
• Repair or replace damaged wiring.
• Reprogram or replace the ECM if necessary.
• Multimeter
• OBD-II scanner
• Basic hand tools
$150 - $500
Moderate
• BMW 7 Series
• Mercedes-Benz S-Class
• Audi A8
• Regular maintenance checks
• Ensure proper cooling system function
• Use high-quality ignition components
Engine Performance
• Avoid driving the vehicle until repaired.
• Consult a professional mechanic for diagnosis.
• Regularly check engine components for wear.
Check with the vehicle manufacturer for warranty coverage on ignition components.
This code is relatively uncommon and typically associated with high-performance or luxury vehicles with more than 8 cylinders.
High – Ignoring this issue can lead to engine damage.
Driving with a misfiring engine can be dangerous and may lead to further mechanical issues.
• Engine at operating temperature
• Vehicle stationary
The ignition coil for cylinder 12 is typically located on the engine's cylinder head, near the spark plug.
Q: Can I drive my car with this code?
A: It's not recommended as it can cause engine damage.
Q: How do I know if my ignition coil is bad?
A: Symptoms include engine misfires, reduced performance, and a check engine light.
High-End · Full-system diagnostics
A full-system bidirectional platform aimed at advanced DIY users and professional diagnostic workflows.
Network faults often require full-system access instead of a generic code reader alone.
View on Amazon
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.
View on Amazon
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.
View on AmazonThese are optional diagnostic tools, not guaranteed fixes. As an Amazon Associate I earn from qualifying purchases.
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.
View options on Amazon
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.