The electrical power of the Toyota ignition coil is how the spark plugs can receive the current that makes it possible to ignite the air and fuel mixture in the combustion chambers of the engine. There can be several ignition coils on any Toyota engine that has been produced. This includes the older models with distributors that only used one coil all the way up to the modern models of Toyota with intergraded electronic ignition using a coil for each plug. The ignition coil is connected to the on board computer today. In the past the Toyota ignition coil was connected to the electrical harness that received its power from either the battery or the alternator. With the newer models, the ignition coil his directly connected to each of the spark plugs by a set of spark plug wires. The need for a distributor is no longer required since the onboard computer is now the device that determines the timing and the voltage that is to be sent to each of the spark plugs. To locate the coil under the hood of your vehicle, just trace the spark plug wires back to their source on the modern models. If you do have a distributor on your engine, the center wire on the distributor cap can be traced back to the ignition coil. This is an ignition component that should last for many years, but like all electrical components on all makes and models of vehicles, it will fail in time from being used. When this does occur on your Toyota, the spark plugs will not fire causing the engine not be able to start no matter how many times the engine is turned over.