What are the reasons for the persistent illumination of the engine malfunction indicator light in the Sail?
2 Answers
The reasons for the illumination of the engine malfunction indicator light in the Sail mainly include the following 7 aspects: Sensor malfunction: The sensors referred to here include those for coolant temperature, crankshaft position, air flow, intake air temperature, oxygen sensors, etc. When these sensors are damaged, have poor contact, or experience signal interruption, the vehicle's ECU cannot accurately obtain engine data, which will trigger the engine malfunction light. Fuel quality issues: If fuel and engine oil are not added as required by the manufacturer, it may cause engine wear and lead to the illumination of the malfunction light. Poor combustion of the air-fuel mixture: Poor combustion can lead to engine carbon deposits or knocking. When detected by the oxygen sensor and reported to the ECU, the malfunction light will illuminate as a warning. Issues such as spark plug failure, ignition coil failure, fuel pump failure, or clogged fuel lines can all cause poor combustion of the engine's air-fuel mixture. Turbocharging problems: Issues with the intake boost pipes or turbocharger can also cause the engine malfunction light to illuminate. The most common issue is turbocharger damage, accompanied by symptoms such as oil leaks, excessive oil consumption, reduced power, metallic noises, or blue/black smoke from the exhaust. Intake problems: If there are issues with the vehicle's air intake, it may lead to clogged engine pipes, and in severe cases, the engine malfunction light will illuminate. A dirty air filter that is not cleaned regularly can cause intake problems. Exhaust problems: Exhaust system faults can also trigger the engine malfunction light. Common causes include issues with the rear oxygen sensor, catalytic converter, exhaust camshaft, or bearings. The catalytic converter is the most frequent culprit. The use of leaded gasoline, lead- or silicon-containing lubricant additives, physical damage to the catalytic converter, or faults in the engine's fuel supply system can all lead to catalytic converter failure. Anti-theft system malfunction: If the vehicle's electronic anti-theft system malfunctions or if the anti-theft controller is incompatible with the engine's electronic controller, the anti-theft system can prevent the engine from operating normally and cause the malfunction light to illuminate. If the engine malfunction light is illuminated, follow these steps: First, check whether the engine is running normally and if there are any issues such as shaking or black smoke. If so, avoid restarting the engine. Note: Do not restart the engine if the red warning light is on. If the engine can be started, turn it off and wait for 5-10 minutes. Without pressing the brake, press the start button once or turn the key halfway to the 'on' position without depressing the clutch. The vehicle will enter self-diagnosis mode after powering on. Wait for 5-10 seconds and observe whether the malfunction light on the dashboard turns off. If the malfunction light remains on, visit a service center as soon as possible. The service center can use a portable diagnostic tool to read the fault codes, identify the issue, and perform targeted repairs.
When the engine warning light on the Sail stays illuminated, based on my experience, this typically indicates the engine control unit has detected an issue. The most common cause is a faulty oxygen sensor, which monitors exhaust gas composition - when contaminated or malfunctioning, it triggers the persistent light. Aged spark plugs or defective ignition coils can also activate the warning due to inaccurate combustion causing abnormal emissions. Additionally, fuel system problems like a clogged fuel pump or dirty fuel filter leading to insufficient supply will illuminate the light. A blocked catalytic converter severely impacts performance too. Loose wiring connections in the engine bay or faulty sensors such as the mass airflow meter are potential culprits as well. I'd recommend promptly using an OBD scanner to retrieve trouble codes for precise diagnosis. Prolonged neglect may lead to more severe engine damage, increased fuel consumption, and compromised driving safety.
