Nearly 30 years of obsessively cataloging, photographing, and taking video of each part means it will fit your 2003 Buick LeSabre ECM ECU - All Models with OEM Number 12583826 Engine Control Module ECM ECU.
Period. No Hassle. GUARANTEED.
We cover round trip shipping if we make a mistake.
Check out the video below to view the Guaranteed Exact Fit process from start to finish!