I have a 2001 Isuzu Trooper with 110000 milage. I bought it six months ago. Yesterday, the check the engine light came up. Also TOD {Tarque on Demand] light is coming up ocassionally. What is the effect and function of TOD? What do i need to do to solve these problems?
That [b] CEL[/b] (check engine light) is just a kid in class waving her hand trying to get you attention because she has the answer. You need to have the codes read. Some places will read them for FREE. Try Autozone or Advanced Auto Parts. Get the exact code (like P0123) not just their translation into English and post it back here.
[b] Tarque [/b] ??? I have no idea, but it should be in your owner's manual. Even if the car did not come with an owner's manual, I strongly recommend buying one (search on the internet) as there is a lot of good information in there, stuff you really should know about your car.Very good insight Joseph. Well, driving is not enough we should know how to fixed our own cars. 
Thank you Joseph. I appreciate your advice.