AEM 30-6905 Universal Programmable EMS-4 - Manual (Page 204)

Page 204 of 279 EMS-4 Install and Tuning Guide_Rev 1.6
As shown above, GPIO5 is set up as a fuel pump function output. It will follow all rules
associated with a fuel pump function:
1. At power up, the output will activate and stay on for the length of time defined for Fuel
Pump Prime above.
2. If no crank tooth pulses are detected, the output will turn off.
3. If crank tooth pulses are detected (engine spinning), the output will turn on to activate
the fuel pump.