When the car encounters water, it can affect the proper functioning of these components, leading to the check engine light being triggered as a precaution. Additionally, water may enter electrical connections within the engine compartment, causing temporary issues that can temporarily activate the check engine light.
Here's a more detailed explanation of what happens when you drive through water:
1. Catalytic Converter Submersion: Driving through deep water or attempting to traverse flooded areas can cause water to enter the exhaust system and reach the catalytic converter. Water can damage or contaminate the internals of the catalytic converter, affecting its ability to efficiently convert harmful pollutants into less harmful substances. This prompts the check engine light to illuminate.
2. Oxygen Sensor Issues: Oxygen sensors monitor the amount of unburned oxygen in the exhaust system, helping the engine control unit (ECU) adjust the air-fuel mixture for efficient combustion. Water intrusion can damage or temporarily affect these sensors, causing incorrect readings that trigger the check engine light.
3. Electrical System Malfunction: Water can sometimes breach electrical connections and components in the engine bay. This can lead to temporary malfunctions and cause various sensors or modules to provide irregular readings or experience glitches. As a result, the check engine light may come on due to these transient electrical issues.
4. Evaporative Emission Control System (EVAP) Issues: The EVAP system is responsible for controlling and preventing fuel vapors from escaping into the atmosphere. If water enters the EVAP system, it can cause issues with vacuum lines or sensors, potentially leading to the check engine light being activated.
5. Diagnostic Trouble Codes: When triggered, the check engine light stores diagnostic trouble codes (DTCs) that provide more specific information about the identified issues. A diagnostic scan using a specialized tool is necessary to retrieve and interpret these trouble codes, which can then help mechanics identify the root cause and perform appropriate repairs.
If the check engine light comes on after driving through water, it is recommended to have the car inspected by a qualified mechanic or technician as soon as possible. Driving with a persistent check engine light can have implications for vehicle performance, fuel efficiency, and emission compliance.
