3. Check A/F Sensor 1 Input Signal Circuit

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

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

Fig 1: Disconnect Corresponding A/F Sensor 1 Harness Connector
Courtesy of NISSAN MOTOR CO., U.S.A.
Disconnect ECM harness connector.
Check harness continuity between the following terminals.
Refer to WIRING DIAGRAM.

Fig 2: Check Harness Continuity Between The Following Terminals
Courtesy of NISSAN MOTOR CO., U.S.A.
1. Continuity should exist.
Check harness continuity between the following terminals and ground.
Refer to WIRING DIAGRAM.

Fig 3: Check Harness Continuity Between The Following Terminals And Ground
Courtesy of NISSAN MOTOR CO., U.S.A.
1. Continuity should not exist.
Also check harness for short to power.

OK or NG

OK: GO TO 4.
NG: Repair open circuit or short to ground or short to power in harness or connectors.