The ignition coil plays a vital role in the ignition system's ability to create combustion. It boosts the power from the battery into a high-voltage spark to trigger the spark plugs. In a Toyota Corolla, the ignition coil mounts directly to the cylinder head, making the system a distributorless ignition system (DIS).
Isolate the negative battery cable to prevent injuries or accidents. You'll need to remove the ground cable from the negative battery terminal post in order to do this.
Loosen and detach the nuts and the clips that secure the cylinder head cover to the cylinder head. The only tool you should need for this is a wrench or a socket set.
Determine whether you need to replace a single ignition coil or all the ignition coils. Each coil connects to a cylinder head and is held in place by a connector.
Remove the connector from the Corolla ignition coil. If you need to remove all of the ignition coils, you should remove a total of four connectors.
Pull up and twist on the ignition coil to free it from the cylinder head.
Verify that the new ignition coil works with your type of engine; universal and stock replacement ignition coils work with select models. Install the new Corolla ignition coil.
Secure the parts in place and reconnect the battery.
