Nissan Repair: ECU / coolant problem?, negative battery cable, mass airflow sensor

Question
My wife's 95 maxima (3.0 auto)overheathed due to lack of engine coolant and the car went into some kind of "fail safe" mode.  Specifically, the car Idles great and handles acceleration great until it reaches 2000 RPM's.  I replaced the coolant, disconnected the negative battery cable for 24 hours and restarted the car with the same results.  I am unable to rev the car over 2000 RPM's and the temp gauge is normal.  I was told that when the car overheats that the ecu does in fact place the car in a fail safe mode to keep the engine temp from going over a certain level.  I think I've fixed the coolant problem, but I don't know how to reset the ECU to allow the engine to rev above 2000 RPM's.  Please Help.

Answer
George,

If the check engine light is on get the codes checked at Autozone or Checker for free.  If the light is not on you probably have a coil that has gotten too hot or you could have another sensor that has gone bad due to the overheating.  I would check the mass airflow sensor too.  Now, get a Haynes book to get the values on the sensors and a volt ohm meter.  The book can be purchased for $20 bucks and so can a volt ohm meter.  Email me back with what you find.  To reset the light, if it is back on, you can disconnect the battery for five minutes or go back to one of the parts stores mentioned above and they will clear it.