wrench

I have a 1995 Honda Accord that recently had the AT transmission swapped by a local mechanic but it does not shift out of first gear....only first gear and reverse works...The mechanic said its a sensor, but did not have the equip. to read the computer... any ideas exactly what sensor would cause the trans not to shift. I was thinking there may be something unplugged if this is the case...

Help! Help! Help! Help!

Thanks,

Wrench