Powertrain Control Module (Pcm): Removal
WARNING: This page does not describe the selected car, but rather 29 other vehicles, including the 1999 Pontiac Montana, 1999 Oldsmobile Silhouette, 1999 Oldsmobile Bravada, 1999 GMC Yukon, and 1999 GMC Sonoma. However, it is still accessible from the selected car via links, so may be relevant.
Ensure ignition switch is in OFF position. Disconnect negative battery cable. Disconnect harness connectors from PCM. Remove PCM from vehicle. On 4.3L, 5.0L, 5.7L and 7.4L, remove access cover and remove knock sensor module from PCM.