ECM & TCM
WARNING: This page is about a different car, the 2003 Saturn Vue and 2002 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.
The ECM is mounted to the intake manifold on the front side of the engine beneath the outlet resonator/duct assembly. The TCM is located on left front strut tower. See Fig 1 . ECM and TCM control ignition, fuel and emission devices related to engine and transaxle upshifts and downshifts.
The TCM receives electronic signals from sensors and switches. These signals help TCM determine when to operate various relays and solenoids related to engine and transaxle control.