You may be low of brake fluid, or your brakes pads may be worn out. Inspect the system.
if your taillights stay on after you turn car off, check your brake pedal light switch or the rubber grommet on the pedal that contacts the switch. if your dash "brake" light stays on while car is on check fluid level. if level is good check the brake fluid level sensor/switch. if there are no leaks and oil level is low, pads are more than likely about to be at their minimum wear thickness. dont just add fluid to turn light off, instead replace worn out pads. Another possible sensor malfunction would be the parking brake sensor which is mounted somewhere next to parking brake(a.k.a. emergency or hand brake).
2003 accord has internal non-servicable float with external sensor so if fluid is at max and pads are good and e-brake switch is good etc., change master cylinder reservoir.
If you are referring to the brake light then the brake light switch is stuck.
Problem with the ABS, take it to a pro.
Brake system-comes on briefly when activated or stays on if trouble like low fluid (or other) in system
If a gas light stays on a 2000 Honda Accord the fuel sensor is malfunctioning. Replacement of the sensor is advised as the car will run of safe mode if the ECU believes it is low on gas.
The ABS light is the light for the Anti-Lock Brake system. If the light stays on then there is a problem with the system. Your normal brakes will still work, but your ABS may not. Have it looked at by a professional.
check brake fluid
If a 2000 Honda Accord gas light stays on the fuel sensor may be failing. Running a diagnostic tool will show if the fuel gauge sensor is malfunctioning.
The SRS lights says on when then is a problem with your air bag system. You need to take your Honda Accord into a service center to get it serviced.
It's telling you the brakes need attention. Have a trusted garage check it out now!
A 2000 Honda Accord check engine light will stay on if the ECU is not reset. To reset the light remove the ECU fuse from the engine bay fuse box. Reinsert it after 5 seconds.
You have a problem with the emissions system. Seek professional help.
The light is on because the alternator is not putting out the required voltage. Either the belt is broken, loose, or the alternator is defective.