Ignition coils
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The ignition coils supply the spark plugs with high voltage to produce sparks. The engine control module (ECM) controls the ignition coils so that sparks are generated at the correct time.
Each ignition coil has its own integrated power stage.
The ignition coils are in the sparkplug wells above each spark plug.
The ignition coils transmit a PWM signal to the engine control module (ECM). The diagnostic signal is transmitted to the engine control module (ECM) if the voltage in the ignition coil exceeds a preset value. The engine control module (ECM) is then able to check that the relevant ignition coil is working.
The engine control module (ECM) can diagnose the ignition coils.