Diagnostic Procedure
WARNING: This page is about a different car, the 2003 Nissan Pathfinder. However, it is still accessible from the selected car via links, so may be relevant.
- Turn ignition off. Disconnect appropriate HO2S 1 4-pin harness connector. See Fig 1 or Fig 2 . Turn ignition on. Measure voltage between ground and appropriate HO2S 1 harness connector terminal No. 3 (Red/White wire). See Figure. If battery voltage exists, go to next step. If battery voltage does not exist, repair as necessary.
- Turn ignition off. Disconnect ECM 116-pin harness connector. ECM is located behind instrument panel lower cover. See Figure. If suspect oxygen sensor is bank 1 sensor, check continuity of Blue/Orange wire between HO2S 1 harness connector terminal No. 2 and ECM harness connector terminal No. 24. See Fig 5. For bank 2, check continuity of Red/Green wire between HO2S 1 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. If no problem is found, go to next step.
- Measure resistance between suspect oxygen sensor harness connector terminals as specified. See CHECKING HO2S 1 RESISTANCE table. See Figure. If resistance and continuity are as specified, go to next step. If resistance or continuity is not as specified, replace HO2S 1.CHECKING HO2S 1 RESISTANCE
Measure Between Terminals No. Specification (Ohms) 2 & 3 2.3-4.3 @ 77°F (25°C) 1 & 2, 1 & 3, 1 & 4 No Continuity 2 & 3, 2 & 4 No Continuity - No problem is indicated at this time. Problem may be intermittent. See INTERMITTENTS in TROUBLE SHOOTING - NO CODES article.