Nissan Repair: electric overdrive, electric overdrive, nissan transmission

Question
I have a 1999 Nissan Frontier XE 4 cylinder automatic with a push button overdrive.   When the overdrive button is in the out position the overdrive off light does not come on.  When I am driving with the overdrive buttoon in and I press it, I can feel no shift. Could you tell me what could be wrong.

Answer
George,

There are several conditions that allow the overdrive and lock up torque converter to engage.  The first is operating temperature.  The second is a light load as in high vacuum on the vacuum switch.  Then, the transmission is set for overdrive to work and once forth gear applies the lock up torque converter locks.  If you press the gas a little the lock up converter disconnects and then the car will downshift to third gear.  A transmission shop with a Nissan transmission scanner can pull any codes that are present if you want to know if any are set.