YOU WILL NEED TO HAVE IT PROGRAMMED BY SHOP WITH ob2d programming software (Launch X431 we recommend). Your VIN# must be added to it along with linking your car key immobilizer or IT WILL NOT WORK! This would be the case on ANY ECM you buy, used or new.  The immobilizer and VIN# have to be added to the ECM or car will run for seconds and turn off. 
YOU DO NOT need new keys etc - this is not true. 

Up for sale is a FACTORY OEM ECM/PCM - complete new unit - not a mile on it.  We do not need the core since we are selling off old stock. 

Only fits what is listed below. No miles on it! 
 
FITS
2001 Sentra 2.0L - (AUTOMATIC Transmission With Anti- Theft)
 
The number on your old one must match: 
23710-4M865
2371M-4M865RE
23710-4M866
2371M-4M866RE
23710-4M867
2371M-4M867RE
23710-4M877
2371M-4M877RE
23710-4M878
2371M-4M878RE
23710-4M879
2371M-4M879RE