4. Check Ho2S1 Input Signal 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.

Disconnect ECM harness connector.
Check harness continuity between ECM terminal and HO2S1 terminal as follows:

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

Continuity should exist.

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

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

Continuity should not exist.

Refer to WIRING DIAGRAM .
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.