Engine warning light on ('check engine')

The engine malfunction light (often an orange engine silhouette, "check engine" / MIL) stays on the dashboard. This is a feature specific to fuel-injected motorcycles (modern four-strokes): a control unit (ECU) continuously monitors the sensors and engine management components, and when it detects an abnormal value or out-of-tolerance operation, it lights this warning and logs a fault code, readable by a professional with a diagnostic tool. Depending on severity, the bike may enter "limp mode": the control unit limits power and adopts a safety fuel map to protect the engine (and the catalytic converter). Possible causes are numerous and almost all electronic: a failed oxygen (lambda) sensor (poor mixture regulation), a faulty injection sensor (throttle position, intake pressure, temperature), a clogged or failing injector, or ignition misfires detected by analyzing engine speed (a tired spark plug or coil). The distinction comes from associated symptoms: power loss (limp mode)? Misfires/jerking under acceleration? Abnormal smoke? The only reliable way to pin down the exact cause remains reading the fault code with a diagnostic tool. Urgency threshold: an engine warning light with no other symptom generally allows careful riding to the garage, but a warning light accompanied by significant power loss, marked misfires, or smoke should be diagnosed quickly — riding a long time with a mixture that's out of spec can damage the engine and the catalytic converter. Except for a simple identified cause (spark plug), most of these faults call for professional diagnosis with a tool.