Mechanic Q: the light of the engine or transmission is on. What is that mean??

My lexus es300, 2008. have a light of the engine or a transmission picture light on. What seem to be the problem?

Mechanic Q: my brake light on all the time even the engine is off. Can you tell me what is the likely problem? ?

my brake light on all the time even the engine is off. Can you tell me what is the likely problem? 1998, nissian quest, mini van.