2003 Camry 2.4 ,has overdrive occasionally ,mostly not...changed coolant tamp sensor,checked switch in shifter,,it just will not engage,,when it does engage,i noticed it's hard to kick back down to 3rd,,,the overdrive off light never comes on,,even if i hit the switch .............any help appreciated

 

The light is supposed to be ON only when the O/D is turned OFF. Is this happening?

 

the light will not come on ,no matter what i do

 

Not sure.

The light is a diode which seldom fails.

Perhaps the switch?

The switch grounds a terminal on the engine computer via a (white/black wire). Check ground connection.

 

i jumped the wire on the switch,,the motor has been changed,checked the vin,and it supposedly has 256,000 miles but odometer shows 136,,,i don't know if the ecu has been changed,,,,,,is milage stored on ecu ???so i could have a bad ecu,,but how do i test,,,,,i have no check engine lights on,,,i'm confused

 

The miles are stored in the instrument cluster. Perhaps this was changed.

The miles may also be stored in the ECU and if so could be accessed by the dealer.

My opinion given your last post is the engine change, odometer variations and who knows what else, is the problem.

The O/D system works through the engine computer. The switch is connected to both the light and computer. The switch itself does not turn the light on, but works through the computer.

If the switch is working OK, then the issue appears computer, trans or wiring.

Suggest you look at the computer, engine and trans to determine if it is they are right ones. That the wiring to them is is correct.

 

For sale !!!!!!!!!!!!!!!!

 

Yes, perhaps the best idea.