Diagnosis Procedure

WARNING: This page is about a different car, the 2020 Infiniti QX60. However, it is still accessible from the selected car via links, so may be relevant.

CHECK DTC PRIORITY
If DTC P0090 is displayed with DTC P1197, first perform the confirmation procedure (trouble diagnosis) for DTC P1197.

Is DTC P1197 detected?

YES

Perform diagnosis for P1197. Refer to DTC Description .

NO

GO TO 2.
CHECK HIGH PRESSURE FUEL PUMP CONTROL CIRCUIT
Check high pressure fuel pump control circuit. Refer to Component Function Check .

Is inspection result normal?

YES

GO TO 3.

NO

Repair or replace error-detected parts.

CHECK HIGH PRESSURE FUEL PUMP CIRCUIT

Turn ignition switch ON.
Disconnect ECM harness connector and high pressure fuel pump harness connector.

Check the continuity between ECM harness connector and high pressure fuel pump harness connector.

ECM		High pressure fuel pump		Continuity
Connector	Terminal	Connector	Terminal
F78	9	F96	2	Existed
	10		1

Also check harness for short to power and short to ground.

Is inspection result normal?

YES

GO TO 4.

Repair or replace the error-detected parts.

CHECK HIGH PRESSURE FUEL PUMP
Check high pressure fuel pump. Refer to Component Inspection (High Pressure Fuel Pump) .

Is inspection result normal?

YES

INSPECTION END

NO

Replace the error-detected parts.