What Causes the Malfunction Light to Illuminate on Rainy Days?

[DelGiselle]

Generally, there are several main reasons that can cause the engine malfunction light to illuminate. 1. Sensor issues: The sensors mentioned here include 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 then trigger the engine malfunction light. 2. Maintenance issues: Poor engine maintenance is the most common cause of the engine malfunction light illuminating. Vehicles have specific maintenance cycles, and if the owner does not adhere to the maintenance schedule and has poor driving habits, it will increase the burden on the engine's operation. 3. Fuel quality issues: The fuel quality here includes both fuel and engine oil. The fuel added to a car usually has a specific grade, and engine oil can be semi-synthetic or fully synthetic. Manufacturers generally recommend which grade of fuel and type of engine oil owners should use. If the owner does not follow these recommendations, it can lead to engine wear over time.