99 Camry brake warning light
 

My Camry dash brake warning light has started coming on while car is being driven. It usually goes off after braking but often will come back on. It seems to do this more often in cooler temperatures. This morning the temperature was in the 40s and light stayed on most of the time. This afternoon temperature was in 50s and the light did not come on during the drive home. I've checked and added brake fluid which had no effect. I do not have means to check for error codes. Any ideas of what the problem may be would be appreciated.

Thanks in advance

Check the tail light and brake bulbs. Clean the bulb and socket electrical contacts.

If you think the issue is the brake fluid level, disconnect the plug.