Are you troubleshooting a (like no-start or limp mode)? 2007 Nissan Navara D40 YD25 PCM Circuit Diagram - Type 1
The ECU outputs a ground signal to trigger the main relay, which then feeds high-amperage power back to the unit. yd25 ecu pinout free
The ECU uses this pin to ground the main relay, closing the circuit to power up the rest of the engine sensors. Are you troubleshooting a (like no-start or limp mode)
Ultimate Guide to YD25 ECU Pinout Diagram: Troubleshooting & Wiring yd25 ecu pinout free