What Causes the Engine Warning Light to Illuminate and the Vehicle to Shake?

[Lily]

When the engine warning light comes on accompanied by vehicle shaking, the primary cause is poor combustion of the air-fuel mixture. This incomplete combustion leads to carbon buildup in the engine, which constitutes the most significant reason for vehicle vibration. Additionally, when oxygen sensors detect this poor combustion and report it to the ECU, the system triggers the warning light as an alert. This explains why both symptoms often occur simultaneously. Several components can contribute to poor air-fuel mixture combustion, including faulty spark plugs, defective ignition coils, malfunctioning fuel pumps, or clogged fuel lines. When the engine warning light activates, follow these steps: First, assess whether the engine is operating normally. Check for symptoms like shaking, black smoke emissions, or difficulty starting. If any of these issues are present, avoid restarting the engine. Important note: Never attempt to restart if the red warning light is illuminated. If the engine appears to be functioning normally and the vehicle can be driven safely, proceed to a service center promptly for diagnosis. Technicians can easily retrieve trouble codes using a portable diagnostic tool, enabling targeted repairs based on specific fault information. For vehicles with normal engine operation, owners may attempt these troubleshooting measures: gently reseat all wiring harness connectors (as loose connections may be the culprit), or repeatedly turn the ignition key to the ON position to see if this clears the warning light.