An illuminated malfunction indicator lamp (MIL) in a Toyota vehicle, which exhibits a blinking or intermittent on-off pattern, indicates a potentially serious issue within the engine management system. This visual signal is designed to immediately alert the driver to a problem that requires prompt attention. For example, a rapid flashing may occur during conditions that could damage the catalytic converter.
Ignoring this warning can lead to significant engine damage and costly repairs. The blinking light signifies a more urgent situation than a continuously illuminated light. The diagnostic system is detecting a misfire or another condition that is introducing unburnt fuel into the exhaust system. The catalytic converter is not designed to handle raw fuel and can overheat and fail. Early diagnosis and repair can prevent such outcomes and ensure the vehicles longevity and continued efficient operation.