Removal (4.2L)
WARNING: This page is about a different car, the 2003 Oldsmobile Bravada, 2003 GMC Envoy XL, 2003 GMC Envoy, and 2003 Chevrolet TrailBlazer. However, it is still accessible from the selected car via links, so may be relevant.
Ensure ignition is off. Disconnect negative battery cable. Locate PCM at left front of engine, on intake manifold plenum. See Fig 1. Loosen PCM harness connector bolts. Disconnect PCM harness connectors. Remove 4 PCM mounting bolts. Remove PCM from intake manifold plenum.