What Does It Mean When the Car Engine's Yellow Light Comes On?

2 Answers
Malia
07/25/25 11:55am
The car engine's yellow light indicates a fault in the engine's exhaust system. If it turns off a few seconds after starting the engine, it means the system is undergoing a normal self-check. If it stays on continuously, there may be a fault in the exhaust system. If it flashes, it indicates engine misfiring, which could damage the catalytic converter. To determine the exact cause, professional diagnosis is required. When the engine (exhaust system) warning light is on, if the coolant temperature gauge and oil pressure warning light are not activated, the vehicle can still be driven. However, it is essential to drive cautiously at a slow speed and seek the nearest auto repair shop for inspection. If the coolant temperature is too high or the oil pressure warning light is also on, and you can clearly feel the vehicle malfunctioning, you should immediately pull over and request assistance.
Was this review help?
15
2
Share
DelJasmine
08/11/25 8:08pm
Oh no, my car's check engine light is on yellow, which is quite common in older vehicles. It's mainly due to aging or dirty oxygen sensors causing inaccurate exhaust monitoring and triggering the light; it could also be a clogged or faulty catalytic converter leading to excessive emissions. Don't overlook issues with spark plugs or ignition coils—misfiring can cause severe engine shaking. Clogged fuel injectors in the fuel system or a faulty mass airflow sensor are also common culprits. A vacuum leak can cause air intake imbalance. My advice is to quickly scan for trouble codes using a Bluetooth OBD tool and act based on the codes. Minor issues can be fixed by cleaning sensors yourself, but for serious problems, head to a repair shop—safe driving shouldn't be ignored. Regular maintenance can help prevent this issue.
Was this review help?
5
5
Share
Expand All
More Forum Discussions

What kind of engine oil should be used for the three-cylinder Excelle?

The three-cylinder Excelle uses 5w30 engine oil, where 5 indicates the low-temperature fluidity of the oil, w stands for winter, and 30 represents the oil's high-temperature resistance index. The Excelle is a compact car under SAIC-GM Buick, with body dimensions of 4609mm in length, 1798mm in width, and 1486mm in height, a wheelbase of 2640mm, a fuel tank capacity of 44 liters, and a body structure of a 4-door 5-seater sedan. The Excelle is equipped with a 1.3T turbocharged engine, paired with a 6-speed automatic manual transmission, delivering a maximum horsepower of 163PS, a maximum power of 120kW, and a maximum power speed of 5500rpm per minute.
20
0
Share

What should be added to a brand-new car?

For a brand-new car, the following items should be added: 1. Apply car window film. Direct sunlight on car windows can rapidly increase the interior temperature, potentially causing sunburn. 2. Install a dash cam. It records the driving process, ensuring the driver's safety. 3. Apply car protective paint. Since new cars are often stored outdoors before purchase, timely application of protective paint helps maintain the car's appearance. Additional details to note when purchasing a new car: 1. Check if all accompanying documents are complete. 2. Carefully confirm whether the car is a display model, stock car, test drive vehicle, faulty car, or accident car. 3. Verify the odometer reading. A new car should have less than 50 kilometers. 4. Inspect the car's exterior for scratches or dents.
8
1
Share

How to Solve the Auto Hold Malfunction in Roewe i5?

Solutions for the auto hold malfunction in Roewe i5: 1. Adjust the parking brake and control lever; 2. Adjust the brake drum clearance. The Roewe i5 is a compact car under the SAIC Motor Corporation Limited, with body dimensions of 4601mm in length, 1818mm in width, 1489mm in height, a wheelbase of 2680mm, a fuel tank capacity of 45 liters, and a trunk capacity of 512 liters. The Roewe i5 is equipped with a 1.5T turbocharged engine, paired with a 7-speed dual-clutch transmission, delivering a maximum horsepower of 169PS, a maximum power of 124kW, and a maximum power speed of 5500rpm.
11
1
Share

What is the difference between Audi RS4 and S4?

The differences between the Audi RS4 and S4 are as follows: From the body style perspective: The Audi RS4 is a station wagon; the S4 is a sedan. From the engine perspective: The Audi RS4 is equipped with a 2.9L twin-turbocharged V6 engine; the S4 is equipped with a 3.0L turbocharged engine. From the body dimensions perspective: The Audi RS4 measures 4782mm in length, 1866mm in width, and 1437mm in height, with a wheelbase of 2826mm; the S4 measures 4770mm in length, 1847mm in width, and 1404mm in height, with a wheelbase of 2825mm. From the tire size perspective: The Audi RS4 uses tires sized 265/35R19; the S5 uses tires sized 255/35R19.
3
3
Share

How to Open a Car Wheel Lock?

Methods to open a car wheel lock: 1. If you have the key, it can be easily opened; 2. If you don't have the key, you need to seek professional help to unlock it, as you cannot open the lock yourself. If your tire is locked, do not attempt to drive away forcibly, as this may damage both the vehicle and the tire. Tires are circular elastic rubber products assembled on various vehicles or machinery to roll on the ground. The functions of tires are: 1. To directly contact the road surface and work with the car suspension to cushion the impact during driving; 2. To ensure good ride comfort and smooth driving; 3. To ensure good adhesion between the wheel and the road surface, improving the car's traction, braking, and passability; 4. To bear the weight of the car.
19
2
Share

What are the reasons for a thermostat failure?

Here are the reasons for a thermostat failure: 1. Due to prolonged warm-up time, the engine operates at a lower water temperature, causing combustion gases and condensed water on the cylinder walls to form acidic substances that corrode the cylinders; 2. Liquid fuel and water wash away the lubricating oil film on the cylinder walls and flow down to the oil pan, diluting the lubricating system's oil, leading to wear on the cylinder liners and piston components; 3. If the cylinder block has defects repaired with adhesive, excessive temperature fluctuations between cold and hot states cause frequent contraction and expansion of the cylinder block, which can lead to adhesive failure or detachment, resulting in diesel engine malfunctions. Additional impacts of a faulty thermostat include: 1. The engine cannot reach its optimal operating temperature; 2. Increased engine wear, shortening the engine's service life; 3. The oil cannot achieve optimal viscosity, increasing engine operating resistance; 4. The engine cannot operate at its normal temperature.
7
1
Share
Cookie
Cookie Settings
© 2025 Servanan International Pte. Ltd.