To find it precisely:
* Consult your owner's manual: This is the best source for the specific location in your truck.
* Look for a fuse box near the PCM: The PCM often sits near the main under-dash fuse box or a secondary fuse box.
* Check online forums: Search for "1997 Chevy pickup PCM location [your engine type]" on forums like Chevrolet forums or truck-specific forums. Adding your engine size (e.g., 4.3L, 5.7L) will significantly narrow the search.
* Visual inspection: Carefully examine areas under the dash and under the hood, looking for a relatively large electronic module with numerous connectors. It will likely have labels or markings identifying it as the PCM or ECM (Engine Control Module - sometimes used interchangeably).
Important Note: Be cautious when working near the PCM. Avoid touching any of the electrical connectors. Disconnecting the battery's negative terminal before working on or near it is a good safety precaution.