Diagnostic Procedure
WARNING: This page is about a different car, the 2002 Nissan Sentra. However, it is still accessible from the selected car via links, so may be relevant.
- Turn ignition off. Disconnect HO2S 4-pin harness connector. See Figure and Figure . Turn ignition on. Measure voltage between ground and HO2S harness connector terminal No. 3 (Blue/Red wire). If battery voltage exists, go to step 3. If battery voltage does not exist, go to next step.
- Check the following:
- Harness connectors E9 and F47.
- Harness connectors M19 and E108.
- Fuse block connector M1.
- Fuse No. 8 (15-amp).
- Harness for open or short between HO2S and fuse.
Repair as necessary. Perform DTC CONFIRMATION TEST to verify repair.
- Turn ignition off. Disconnect ECM harness connector. See Figure and Figure . Check continuity between HO2S harness connector terminal No. 2 and ECM harness connector terminal No. 2. Continuity should exist. Also, check circuit for short to ground and short to voltage. If problem is found, repair as necessary. Perform DTC CONFIRMATION TEST to verify repair. If problem is not found, go to next step.
- Measure resistance between HO2S terminals. See Fig 1 and HO2S HEATER RESISTANCE SPECIFICATIONS for terminal selections. If HO2S tests as specified, go to next step. If HO2S does not test as specified, replace HO2S. Perform DTC CONFIRMATION TEST to verify repair.HO2S HEATER RESISTANCE SPECIFICATIONS
Terminal No. Resistance Ohms @ 77°F (25°C) No. 2 and No. 3 2.3-4.3 No. 1 and No. 2, 3, 4 Infinity No. 4 and No. 1, 2, 3 Infinity - Problem is intermittent condition. See INTERMITTENTS in TROUBLESHOOTING - NO CODES article. Perform DTC CONFIRMATION TEST to verify repair.
CAUTION:
DO NOT reuse any HO2S that has been dropped from a height of 20" (.5 m) or more onto a hard surface such as concrete.