No check engine light when key is in on position? This is why

The check engine light is a critical component of a vehicle’s diagnostic system, designed to illuminate briefly when the ignition is in the "on" position, signaling system readiness and identifying potential issues. If this light fails to appear, it could indicate problems such as a blown bulb, faulty wiring, ECU malfunctions, deliberate tampering, or instrument cluster issues. Proper diagnosis involves checking bulbs, scanning the ECU, inspecting wiring, and, if necessary, seeking professional assistance. Addressing this issue promptly is crucial to ensure the vehicle can alert the driver to engine or emissions problems, maintaining both reliability and compliance.