Guaranteed Fit

Nearly 30 years of obsessively cataloging, photographing, and taking video of each part means it will fit your 2003 Chevrolet Trailblazer ECM ECU - 4.2L Engine - OE Number 12574976 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!