The P0627 code in your 2020 Infiniti QX60 indicates an open circuit in the fuel pump control circuit. This circuit activates the fuel pump to pressurize the fuel system. When the ECM commands the fuel pump on but detects no circuit activity, P0627 is stored. This code points to a break somewhere in the control pathway.
Fuel Pump Control System
Your QX60's ECM controls the fuel pump through a relay and driver circuit. When you turn the key to on or start the engine, the ECM energizes the fuel pump relay, which then powers the actual fuel pump. The control circuit is the pathway from the ECM to the relay—separate from the high-current power circuit to the pump itself.
Why Open Circuits Occur
Broken wiring between the ECM and fuel pump relay is common, often from age, vibration, or rodent damage. The fuel pump relay's control coil may have failed open. Corroded or loose connectors break the circuit pathway. A fuse in the control circuit (not just the pump power circuit) may have blown. The ECM's internal relay driver may have failed open.
Symptoms You'll Experience
No fuel pump prime sound when turning the key to on is the classic symptom. The engine cranks but won't start due to no fuel pressure. If the open is intermittent, the vehicle may start sometimes but not others. The check engine light illuminates if the engine does manage to run long enough.
Diagnostic Approach
Using Nissan CONSULT or a compatible scanner, check fuel pump relay command status. Locate the fuel pump relay and check for control signal when commanded. Test for power and ground at the relay control terminals. Use a wiring diagram to trace the circuit from ECM to relay, checking continuity at each segment.