Engine Control Module (Except RPO LY6)

Engine Control Module (ECM) X1 (Gas) (Pin 1 To 30):

Engine Control Module (ECM) X1 (Gas) (Pin 31 To 64):

Engine Control Module (ECM) X1 (Gas) (Pin 65 To 73):

Engine Control Module (ECM) X2 (4.8L/5.3L/6.0L/6.2L) (Pin 1 To 49):

Engine Control Module (ECM) X2 (4.8L/5.3L/6.0L/6.2L) (Pin 50 To 80):