To be certain, you should:
* Consult your owner's manual: This is the best resource for the precise location of all major components in your vehicle.
* Look for a large, rectangular black box with numerous wiring harnesses connected to it. This is a good visual clue for locating the ECM.
If you can't find it using these methods, searching online for "2000 Dodge Grand Caravan ECM location" along with your specific engine (e.g., 3.3L, 3.8L) might yield images or diagrams.