LIGHT ON DURING DAYTIME - 2003 Toyota Corolla

what is the sensor for?

Theres a sensor in the middle of the dash by the front windshield that detects sunlight and triggers the automatic headlights. The main headlights and daytime running lights might be on a different circuit, in which case they daytime running lamps would turn off at night and the main headlights would turn on, indicating the main headlights arent working and the daytime running lamps are working as intended.

I would check all the fuses related to headlights, check the bulbs and check the switch, then last the light sensor on the dash.

light sensor is going bad..or bad light switch. Sensor are usually located in center of dash facing the windshield. Clean it first and see it that helps.

Check the emergency brake pedal and make sure it is not on a bit. When the emergency brake are applied the daytime running light go out.

it should have a fuse or relay says DRL or DAYTIME RUNNING LIGHTS.

its likley to be the head light censor

turn on your headlights during the day. The modular is not repairable

Seeing how I dont know if this is during the night or day, most berettas have daytime and automatic nighttime lights. The dashboard and the lights are connected together and if the sensor is saying that its daytime they are going to switch. I suggest checking your daytime running light sensor to see if it is getting to much saturation of light while driving at night. This could be confusing the computer and turning off the lights. Cant guarentee that this is fix it but its a good place to start.

Do you have a dashmat or any kind of cover on your dashboard? If you look on your dash, you should see a small domed "smoked" lense looking thing. That is a sensor for your daytime/night time automatic lights. If you cover it and block out the light, your vehicle thinks it is dark out. If you don't have anything covering it, you may have a faulty sensor or wiring.

The daytime running lights go on during the day when in drive . Is the anything on the dashboard top covering the light sensor making it think its night