It shows that there is a problem with the transmission. Just like the check engine light, the overdrive light has codes that tell you what is wrong with the transmission and the various components connected with it.
It allows the car to operate at lower revs making for a smoother drive and better fuel consumption at higher speeds. The gearbox will shift into overdrive itself, so it is always best to have it switched on in normal driving conditions. You only need to switch off the overdrive when you need greater engine braking or are towing a heavy load.
What are the advantages of stress interview?
Why the story entitled origin of fair complexion and fair hair?
Ano ang kahulugan ng iskolarling pagpapahayag?
What is a classified data spill or negligent discharge of classified information?
Ano ang papel na ginagampanan ng mga impormasyong ito sa mapa o sa globo?