Overall Function Check

WARNING: This page is about a different car, the 2004 Infiniti I35. However, it is still accessible from the selected car via links, so may be relevant.

Use this procedure to check the overall function of the heated oxygen sensor 1 circuit. During this check, a DTC might not be confirmed.

WITH GST

Start engine and warm it up to normal operating temperature.
Set voltmeter probes between ECM terminal 91 (HO2S1 bank 1 signal) or 92 (HO2S1 bank 2 signal) and engine ground.
Check the following with engine speed held at 2,000 rpm constant under no load.
- The voltage fluctuates between 0 to 0.3V and 0.6 to 1.0V more than 5 times within 10 seconds.
  1 time: 0 - 0.3V --> 0.6 - 1.0V --> 0 - 0.3V
  
  2 times: 0 - 0.3V --> 0.6 - 1.0V --> 0 - 0.3V --> 0.6 - 1.0V --> 0 - 0.3V
  
  Fig 1: Checking Overall Function Of Heated Oxygen Sensor 1
  Courtesy of NISSAN MOTOR CO., U.S.A.
If NG, go to DIAGNOSTIC PROCEDURE .