Open Circuit

If there is no continuity, the circuit is open. Repair or replace the harness.
- Heated oxygen circuit (HO2S connector terminal A and PCM connector terminal 4W (Front)).
- GND circuit (HO2S connector terminal B and PCM connector terminal 4O through common connector (Front)).
- Heated oxygen circuit (HO2S connector terminal A and PCM connector terminal 4AA (Rear)).
- GND circuit (HO2S connector terminal B and PCM connector terminal 4O through common connector (Rear)).
Fig 1: Identifying Front & Rear Heated Oxygen Sensor [BP, BP With TC] Harness Side Connector Terminals
Courtesy of MAZDA MOTORS CORP.