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 HO2S Harness Side Connector
Courtesy of MAZDA MOTORS CORP.