An ignition control module is a small onboard computer used in many older vehicles to control when the spark plugs engage or “fire” inside the engine. This control module relies on data from components such as the crankshaft position sensor, camshaft position sensor, and throttle position sensor to determine the proper timing for the spark plugs and to optimize engine efficiency and power. Many newer vehicles do not have an ignition module. Instead, spark plug timing is controlled by the engine control module (ECM).
If the ignition control module malfunctions, the symptoms that result can mirror those of the components that it controls, namely the coil(s), distributor cap, spark plugs, and spark plug wires. If your vehicle has an ignition module that goes bad, you might notice the following symptoms:
An ignition control module is usually located somewhere in the engine compartment, either on the engine, the distributor assembly, or the firewall (the panel that separates the engine from the passenger compartment).
To replace the ignition control module, a technician will take the following general steps:
