Glow Plug Controller

What is a Glow Plug Controller?

Glow plugs heat the cylinders in diesel engines to help ignite fuel in cold temperatures. Because diesel engines rely solely on compression and engine temperature for combustion, they are known for being harder to start as the temperature drops and rely on glow plugs to ensure the engine can be started in winter weather. Glow plug controllers monitor air and fuel density, as well as engine temperatures, and adjust the current to the glow plugs so the engine can start and run smoothly. A glow plug controller is typically located on the engine or in the engine bay, and is directly connected to the engine control module to ensure consistent communication and allow the glow plugs' operation to be varied as needed. Over time, glow plug controllers may suffer damage or wear and can fail to operate as they should. Symptoms of a failing glow plug controller include white exhaust smoke, poor engine power, rough idle, and misfires. If your diesel engine is hard to start, check the glow plug controller for visible damage, and test the controller's function if possible. It may also be necessary to inspect and test the glow plugs to ensure they are working as they should, as one or more failing glow plugs can cause similar symptoms. O'Reilly Auto Parts carries a variety of glow plugs and glow plug controllers for diesel vehicles to help you make a complete repair and keep your diesel starting in any season.