Low brake fluid in master cylinder, fault in brake fluid level sensor, parking brake is on, parking brake sensor fault.
check the brake fluid level in your master cylinder under the hood. The light comes on for two reasons, either the hand brake is on or your brake fluid level is low
If you press the brake down and the light comes on, a brake light is out. If it is on with your lights on, it means a tail light is out. The warning references are on page 47 (89 celica) manual...
Check your brake fluid level in the brake master cylinder in your engine compartment when it is low your brake warning light will come on
Low brake fluid possible
The brake warning light in a 2002 Ford Windstar can be triggered by several issues. Common causes include low brake fluid levels, a malfunctioning brake light switch, or a problem with the anti-lock braking system (ABS). Additionally, worn brake pads or issues with the brake system's hydraulic components may also activate the light. It's important to address this warning promptly, as it indicates a potential safety concern.
The red " BRAKE " warning light in your dash comes on if the emergency brake / parking brake is on , or if the BRAKE FLUID LEVEL in the brake master cylinder ( located in your engine compartment , near the firewall , on the drivers side of the engine compartment ) IS LOW
Check brake fluid level in master cylinder Check to make sure parking brake is fully released
The transit brake warning light, on a Ford, can be reset by changing the brake pads. If the warning light is still on after changing the brake pads remove the fuse for 10 seconds.
If your vehicle has separate dash panel warning lights for brakes and emergency brakes, then the e-brake light being on while not engaged may indicate that the e-brake switch may be maladjusted or faulty. If the brake warning light is on, it may indicate a brake fluid leak, or in some cases, low brake fluid levels in the reservoir. If your vehicle has a shared warning light for e-brake and brake warning, all causes listed above could apply.
The transit brake warning light, on a Ford, can be reset by changing the brake pads. If the warning light is still on after changing the brake pads remove the fuse for 10 seconds.
Check the brake fluid level, as on many vehicles the "emergency brake" (in the UK, Hand-brake) warning light also acts as a warning light for low brake-fluid.
The engine warning light for emissions might come on in a Toyota Celica if the Oxygen Sensors are bad. It might also come on if the catalytic converter is not working properly or is plugged.