New old stock ACDelco GM 16142151 Memory Calibration Module Replacement 16142151 was replaced with 16159046 on May 1, 1991 for the U.S. market. This part is an engine control module for Chevrolet Trucks, and GMC Trucks cars. Not sure but was told It fits for 16159046 Fits; Chevrolet Trucks S10 pickup 4WD 1991-1994 and GMC Trucks S10 pickup 2WD 1991-1993.Chevrolet Trucks S10 pickup 4WD, and S10 pickup 2WD, GMC Trucks Sonoma 2WD, Sonoma 4WD, Sonoma GT 2WD, Sonoma GT 4WD, Syclone 2WD, and Syclone 4WD for the U.S. from 1990 to 1991. Fitment up to buyer. Made in U.S.A. New old stock (as seen in pictures). I will Pack with care...ship with Insurance and delivery confirmation for your protection THANK YOU FOR LOOKING.