Cool Check Engine Light On F350 Diesel Ideas. I replaced the fuel cap because i wasn't hearing the vacuum hiss it should when twisting off the cap. But now the unit is running fine, but the engine light is still on.
One of the most common reasons for seeing the check engine light on a diesel truck is the aftertreatment system. If you have a flashing check engine light, turn off the engine immediately to prevent potential motor damage. We tested the glow plug and wiring.
