Diagnosis Procedure

CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten ground screws on the body.
  Refer to "GROUND INSPECTION ".
Fig 1: Identifying Body Ground (M70 And M16)
Courtesy of NISSAN MOTOR CO., U.S.A.

OK or NG

OK: GO TO 2.

NG: Repair or replace ground connections.
CHECK AIR FUEL RATIO (A/F) SENSOR 1 POWER SUPPLY CIRCUIT
1. Disconnect air fuel ratio (A/F) sensor 1 harness connector.
  
  Fig 2: Identifying Air Fuel Ratio (A/F) Sensor 1 Harness Connector
  Courtesy of NISSAN MOTOR CO., U.S.A.
2. Turn ignition switch ON.
3. Check voltage between A/F sensor 1 terminal 3 and ground with CONSULT-III or tester.
  Voltage: Battery voltage
OK or NG

OK: GO TO 4.

NG: GO TO 3.

Fig 3: Checking Voltage Between A/F Sensor 1 Terminal 3 And Ground
Courtesy of NISSAN MOTOR CO., U.S.A.
DETECT MALFUNCTIONING PART
Check the following.
- Harness connectors E12, F3
- IPDM E/R harness connector E7
- 15 A fuse
- 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 harness continuity between A/F sensor 1 terminal and ECM terminal as per the following. Refer to SYSTEM WIRING DIAGRAMS article.

ECM CONNECTOR TERMINALS REFERENCE CHART

	A/F sensor 1 terminal	ECM terminal
Bank 1	1	16
	2	75
	5	35
	6	56
Bank 2	1	76
	2	77
	5	57
	6	58

Continuity should exist .

Check harness continuity between the following terminals and ground. Refer to SYSTEM WIRING DIAGRAMS article.

ECM CONNECTOR TERMINALS REFERENCE CHART

Bank 1		Bank 2
A/F sensor 1 terminal	ECM terminal	A/F sensor 1 terminal	ECM terminal
1	16	1	76
2	75	2	77
5	35	5	57
6	56	6	58

Continuity should not exist .

Also check harness for short to power.

OK or NG

OK: GO TO 5.

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

CHECK INTERMITTENT INCIDENT
Perform "DIAGNOSIS PROCEDURE ".

OK or NG

OK: GO TO 6.

NG: Repair or replace malfunctioning part.
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