Why is the engine warning light on in the Beijing BJ40?

[DeEsther]

The main reasons for the engine warning light to illuminate include sensor issues, car maintenance problems, fuel quality issues, poor mixture combustion, engine intake problems, turbocharging problems, exhaust problems, and anti-theft system malfunctions. Additionally, during vehicle startup, the car performs a self-check on the engine system. Normally, the engine warning light will turn off after the self-check is completed. If it remains on for an extended period, it is advisable to seek professional help at a service station to diagnose and eliminate potential safety hazards. Below is a detailed explanation of each type of fault: Sensor issues: Sensors include those for coolant temperature, crankshaft position, air flow, intake temperature, and oxygen. When these sensors are damaged, have poor contact, or experience signal interruptions, the vehicle's ECU cannot accurately obtain engine data, causing the engine warning light to illuminate. In such cases, it is important to visit a service center promptly for professional diagnosis and to eliminate safety risks. Maintenance issues: Poor engine maintenance is one of the most common reasons for the engine warning light to illuminate. Vehicles have specific maintenance cycles, and failure to adhere to these cycles, combined with poor driving habits, can increase the burden on the engine, eventually triggering the engine warning light to alert the owner of a potential issue. Fuel quality issues: This refers to both fuel and engine oil. The fuel used in cars usually has a specific octane rating, and engine oil can be semi-synthetic or fully synthetic. Manufacturers typically recommend which fuel octane rating and type of engine oil to use. If the owner fails to follow these recommendations over time, it can lead to engine wear and trigger the warning light. Always use the recommended fuel octane rating and appropriate engine oil for your vehicle. Poor mixture combustion: Issues such as faulty spark plugs, ignition coils, fuel pumps, or clogged fuel lines can cause poor mixture combustion in the engine. This can lead to engine carbon buildup or knocking, which the oxygen sensor will detect and report to the ECU, prompting the warning light to illuminate as a warning. Intake problems: The engine requires air for combustion, and the air filter plays a crucial role in this process. If the air filter is dirty or not cleaned regularly, it can affect the engine's air intake, potentially leading to blockages over time. In severe cases, this can cause the engine warning light to illuminate. Turbocharging problems: Issues with the intake turbocharging system or turbocharger can also trigger the engine warning light. The most common problem is a damaged turbocharger, which may also cause symptoms such as oil leaks, excessive oil consumption, reduced power, metallic noises, or blue/black smoke from the exhaust. Exhaust problems: Faults in the rear oxygen sensor, catalytic converter, exhaust camshaft, or bearings can cause the engine warning light to illuminate. The most common issue is a faulty catalytic converter, which can be caused by using leaded gasoline, lead- or silicon-containing oil additives, physical damage to the catalytic converter, or fuel system malfunctions. Anti-theft system: If the car's electronic anti-theft system malfunctions or the anti-theft controller is incompatible with the engine control unit, the anti-theft system can prevent the engine from operating normally, causing the warning light to illuminate. Solutions for when the engine warning light is on: If the engine warning light is on and the car cannot start, this may be due to a faulty fuel pump or ignition components. In this case, it is recommended to call for assistance immediately. If the engine warning light is on and the car is drivable but experiences severe shaking or loss of acceleration, pull over safely and call for roadside assistance. If the engine warning light is on but the car drives normally, this may indicate a minor sensor issue. You can continue driving cautiously at low to moderate speeds but should visit a repair shop as soon as possible to address the issue.