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.

NOTE: Turning the ignition switch ON with FRP sensor harness connector disconnected causes ECM to detect DTC P0190. Be sure to erase the DTC when the diagnosis procedure.

CHECK DTC PRIORITY
If DTC P0193 is displayed with DTC P0088 or P0090, first perform the confirmation procedure (trouble diagnosis) for DTC P0088 or P0090.

Is DTC P0088 or P0090 detected?

YES

Perform diagnosis of applicable.
- DTC P0088: Refer to DTC Description .
- DTC P0090: Refer to DTC Description .
NO

GO TO 2.

CHECK FUEL RAIL PRESSURE (FRP) SENSOR POWER SUPPLY-I

Turn ignition switch OFF.
Disconnect FRP sensor connector.
Turn ignition switch ON.

Check the voltage between FRP sensor harness connector terminals.

FRP sensor			Voltage (Approx.)
Connector	+	-
	terminal
F97	3	1	5 V

Inspection result normal?

YES

GO TO 8.

GO TO 3.

CHECK FRP SENSOR POWER SUPPLY-II

Check the voltage between FRP sensor harness connector and the ground.

+		-	Voltage (Approx.)
FRP sensor
Connector	Terminal
F97	3	Ground	5 V

Is inspection result normal?

YES

GO TO 6.

GO TO 4.

CHECK FRP SENSOR POWER SUPPLY CIRCUIT

Turn ignition switch OFF.
Disconnect ECM harness connector.

Check the continuity between FRP sensor harness connector and ECM harness connector.

FRP sensor		ECM		Continuity
Connector	Terminal	Connector	Terminal	Continuity
F97	3	F78	80	Existed

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

Is inspection result normal?

YES

GO TO 5.

Repair or replace error-detected parts.

CHECK SENSOR POWER SUPPLY 2 CIRCUIT
Perform Diagnosis Procedure .

Is inspection result normal?

YES

Perform the trouble diagnosis for ECM power supply circuit. Refer to Diagnosis Procedure .

NO

Repair or replace error-detected parts.

CHECK FRP SENSOR GROUND CIRCUIT

Turn ignition switch OFF.
Disconnect ECM harness connector.

Check the continuity between FRP sensor harness connector and ECM harness connector.

FRP sensor		ECM		Continuity
Connector	Terminal	Connector	Terminal	Continuity
F97	1	F78	83	Existed

Also check harness for short to power.

Is inspection result normal?

YES

GO TO 7.

Repair or replace error-detected parts.

CHECK ECM GROUND CIRCUIT

Check the continuity between ECM harness connector and ground.

ECM		--	Continuity
Connector	Terminal
F78	2	Ground	Existed
	7
F79	87
	88
	95
E32	199
	201
	204

Also check harness for short to power.

Is the inspection result normal?

YES

INSPECTION END

Repair or replace error-detected parts.

CHECK FRP SENSOR SIGNAL CIRCUIT

Turn ignition switch OFF.
Disconnect ECM harness connector.

Check the continuity between FRP sensor harness connector and ECM harness connector.

FRP sensor		ECM		Continuity
Connector	Terminal	Connector	Terminal	Continuity
F97	2	F78	53	Existed

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

Is inspection result normal?

YES

GO TO 9.

Repair or replace error-detected parts.

CHECK FRP SENSOR
Check the FRP sensor. Refer to Component Inspection (Fuel Rail Pressure Sensor) .

Is inspection result normal?

YES

INSPECTION END

NO

Repair or replace error-detected parts.