On most vehicles the fuel pump control module is located on the frame rail near the spare tire.
However some fuel pump control modules may be located more near the fuel tank or may be located under the hood near the firewall on the passenger side.
The location of the fuel pump control module on the vehicle can vary depending on the make and model of the vehicle and whether it's a car, truck, van etc.
But for most trucks and vans the fuel pump control module is located on the frame rail near the spare tire but sometimes the fuel pump control module is located under the hood.
If you enter your cars make and model into Google and then search where the fuel pump control module is located it should show a picture of where your fuel pump control module is located.
The fuel pump control module IS NOT located in the fuel tank.
This fuel pump control module is an entirely separate unit from the fuel pump that monitors the voltage going to the fuel pump, and when it senses anything out of preset parameters, it illuminates the MIL in the instrument cluster.
If we knew the vehicle make and model we could give a better answer.