What is the Engine bay relay module in charge of? The one on the driver side that is under the fuse tray?
Im not talking about the Relacy Control Module.
Is that the keyless entry Relay?
Just wondering​​​​​​.

Here is a pic for reference.

 

Pulse module. Use the search box in upper right corner of forum for additional info. It basically energizes the starter circuit when you turn the key to start

 

There are two relays on that board. One is the starter relay, its contacts close and supply battery power to the solenoid on the top of the starter, it's relay is under control of the ECU.

The second relay is to power the coolant pump for the intercooler in the SRT. If your car is not an SRT, you still have that relay, it does nothing in N/A cars.