DTC Diagnosis Procedure

WARNING: This page is about a different car, the 2019 Nissan NV3500 HD, 2019 Nissan NV2500 HD, and 2019 Nissan NV1500. However, it is still accessible from the selected car via links, so may be relevant.

CHECK GROUND CONNECTION
1. Turn ignition switch OFF.
2. Check ground connection E9. Refer to Ground Inspection in Intermittent Incident .
Is the inspection result normal?

YES

GO TO 2.

NO

Repair or replace ground connection.
RETIGHTEN A/F SENSOR 1
Loosen and retighten the A/F sensor 1. Refer to Removal and Installation (Exhaust Manifold) .

GO TO 3.

CHECK EXHAUST GAS LEAK

Start engine and run it at idle.

Listen for an exhaust gas leak before three way catalyst 1.

Courtesy of NISSAN NORTH AMERICA, INC.

Is exhaust gas leak detected?

YES

Repair or replace.

GO TO 4.

CHECK FOR INTAKE AIR LEAK
Listen for an intake air leak after the mass air flow sensor.

Is intake air leak detected?

YES

Repair or replace.

NO

GO TO 5.
CLEAR THE MIXTURE RATIO SELF-LEARNING VALUE
1. Clear the mixture ratio self-learning value. Refer to Work Procedure .
2. Run engine for at least 10 minutes at idle speed.
Is the 1st trip DTC P0171, P172, P0174 or P0175 detected? Is it difficult to start engine?

YES

Perform trouble diagnosis for DTC P0171, P0174 or P0172, P0175. Refer to DTC Description , DTC Description , DTC Description or DTC Description .

NO

GO TO 6.

CHECK AIR FUEL RATIO (A/F) SENSOR 1 POWER SUPPLY CIRCUIT

Disconnect A/F sensor 1 harness connector.
Turn ignition switch ON.

Check the voltage between A/F sensor 1 harness connector and ground.

A/F sensor 1			Ground	Voltage
Bank	Connector	Terminal	Ground	Voltage
1	F65	1	Ground	Battery voltage

Is the inspection result normal?

YES

GO TO 8.

GO TO 7.

DETECT MALFUNCTIONING PART
Check the following.
- Harness connectors E2, F32
- IPDM E/R harness connector E119
- 15 A fuse (No. 54)
- Harness for open or short between A/F sensor 1 and fuse
Repair or replace harness or connectors.

CHECK A/F SENSOR 1 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT

Turn ignition switch OFF.
Disconnect ECM harness connector.

Check the continuity between A/F sensor 1 harness connector and ECM harness connector.

A/F sensor 1			ECM		Continuity
Bank	Connector	Terminal	Connector	Terminal
1	F65	3	F77	66	Existed
		4		67

Check the continuity between A/F sensor 1 harness connector and ground, or ECM harness connector and ground.

A/F sensor 1			Ground	Continuity
Bank	Connector	Terminal
1	F65	3	Ground	Not existed
		4

ECM			Ground	Continuity
Bank	Connector	Terminal
1	F77	66	Ground	Not existed
		67

Also check harness for short to power.

Is the inspection result normal?

YES

GO TO 9.

Repair open circuit, short to ground or short to power in harness or connectors.

CHECK AIR FUEL RATIO (A/F) SENSOR 1 HEATER
Refer to Component Inspection .

Is the inspection result normal?

YES

GO TO 10.

NO

GO TO 13.
CHECK MASS AIR FLOW SENSOR
Check both mass air flow sensor (bank 1 and bank 2).

Refer to Component Inspection .

Is the inspection result normal?

YES

GO TO 11.

NO

Replace malfunctioning mass air flow sensor.
CHECK PCV VALVE
Refer to Inspection .

Is the inspection result normal?

YES

GO TO 12.

NO

Repair or replace PCV valve.
CHECK INTERMITTENT INCIDENT
Perform Intermittent Incident .

Is the inspection result normal?

YES

GO TO 13.

NO

Repair or replace.
REPLACE AIR FUEL RATIO (A/F) SENSOR 1
Replace malfunctioning air fuel ratio (A/F) sensor 1.
CAUTION:
- Discard any A/F sensor which has been dropped from a height of more than 0.5 m (19.7 in) onto a hard surface such as a concrete floor; use a new one.
- Before installing new A/F sensor, clean exhaust system threads using Oxygen Sensor Thread Cleaner [commercial service tool (J-43897-18 or J-43897-12)] and approved Anti-seize Lubricant (commercial service tool).
INSPECTION END