Where is the ecm on a 91 gmc jimmy s-15 4.3 rwd?

The ECM (Engine Control Module) on a 1991 GMC S-15 Jimmy with the 4.3L RWD is typically located under the hood, on the passenger's side, near the firewall. It's often attached to the inner fender well or secured to a bracket in that general area. However, the exact placement can vary slightly depending on specific options and modifications.

To be sure, you should:

1. Consult your owner's manual: This is the best source for the exact location.

2. Look for a black box with numerous connectors: The ECM is a fairly large, rectangular black box.

3. Check wiring harnesses: Follow the major wiring harnesses leading from the engine compartment; they'll often lead you directly to the ECM.

If you can't find it after checking these locations, a picture of your engine bay might help someone more familiar with the specific model identify it.