3. Check Heated Oxygen Sensor 1 Circuit For Open And Short

WARNING: This page is about a different car, the 2004 Infiniti M45. However, it is still accessible from the selected car via links, so may be relevant.

Turn ignition switch OFF.
Disconnect corresponding heated oxygen sensor 1 (HO2S1) harness connector.
Disconnect ECM harness connector.
Check harness continuity between ECM terminal and HO2S1 terminal as follows. Refer to WIRING DIAGRAM .

Fig 1: Checking Harness Continuity Between ECM Terminal & HO2S1 Terminal
Courtesy of NISSAN MOTOR CO., U.S.A.

Continuity should exist.
Check harness continuity between the following terminals and ground. Refer to WIRING DIAGRAM .

Fig 2: Checking Harness Continuity Between Terminals & Ground
Courtesy of NISSAN MOTOR CO., U.S.A.

Continuity should not exist.
Check harness continuity between HO2S1 terminal 4 and ground.
Continuity should exist.
Also check harness for short to power.

OK or NG

OK: GO TO 5. CHECK FUEL PRESSURE .
NG: GO TO 4.