my Toyota Camry's engine light is on but running fine what's the problem

Solution

1. Preparation

• Gather tools: OBD-II scanner, socket set, multimeter, vacuum gauge.
• Ensure the vehicle is parked on a level surface and the engine is off.
• Disconnect the negative battery terminal to reset the ECU (Engine Control Unit).

2. Retrieve and Analyze Error Codes

• Connect the OBD-II scanner to the vehicle's diagnostic port.
• Turn the ignition to the "ON" position without starting the engine.
• Retrieve and note any stored error codes.
• Consult the vehicle’s service manual or an online database to determine the meaning of the codes.

3. Address Common Causes

• Gas Cap Issue:
  • If the OBD-II scanner indicates a code related to the fuel system (e.g., P0455), check and replace the gas cap if it is damaged or not sealing properly.
• Vacuum Leak:
  • Use a vacuum gauge to test for leaks; repair or replace any faulty hoses or connections.
• Faulty Sensors:
  • If codes point to a specific sensor (e.g., O2 sensor), follow the manufacturer’s specifications to remove and replace the sensor.

4. Clear Error Codes

• After addressing the identified issues, reconnect the negative battery terminal.
• Use the OBD-II scanner to clear any stored error codes.
• Turn the ignition on again to confirm the check engine light is off.