DTC P0136 - Rear Heated Oxygen (O2) Sensor

1. Check Ground Circuit
   
   Turn ignition switch to OFF position. Loosen and retighten engine ground screws. Disconnect rear heated O2 sensor harness connector. See Fig 1. Using an ohmmeter, check continuity between rear heated O2 sensor harness connector terminal No. 3 (Green/Yellow wire) and ground. If no continuity exists, check for faulty joint connector No. 1 or open in Green/Yellow wire. Repair or replace as required. If continuity exists, go to next step.
2. Check Input Signal Circuit
   
   Disconnect ECM harness connector. See Figure. Using an ohmmeter, check continuity between ECM harness connector terminal No. 52 (White wire) and rear heated O2 sensor harness connector terminal No. 2 (Black wire). See Figure. If no continuity exists, repair open in White or Black wires as required. If continuity exists, check continuity between ECM harness connector terminal No. 52 (White wire) and ground. If continuity exists, repair short in White wire. If no continuity exists, go to next step.
3. Check Component
   
   Inspect rear heated O2 sensor. See SYSTEM/COMPONENT TESTS article. Replace rear heated O2 sensor as required. Disconnect and reconnect harness connectors in circuit and perform FINAL CHECK .

Fig 1: Locating Rear Heated O2 Sensor Harness Connector

Courtesy of NISSAN MOTOR CO., U.S.A.