July 1: So it begins. Don't worry, this is not in the correct legal jurisdiction!

Open circuit

If there is no continuity in the following wiring harnesses, there is an open circuit. Repair or replace the wiring harness.
- Front HO2S terminal A and main relay terminal A
- Front HO2S terminal B and PCM terminal 2AD
- Front HO2S terminal D and PCM terminal 2AC
- Front HO2S terminal E and PCM terminal 2BG^*1 ,2G^*2
- Front HO2S terminal F and PCM terminal 2Z
  
  Fig 1: PCM Connector Terminal Identification
  Courtesy of MAZDA MOTORS CORP.

If there is no continuity, there is an open circuit. Repair or replace the wiring harness.
- HO2S terminal A and PCM terminal 2Q^*1 , 2AH^*2
- HO2S terminal B and PCM terminal 2P^*1 , 2AA^*2

If there is no continuity, there is an open circuit. Repair or replace the wiring harness.
- HO2S terminal C and main relay terminal A
- HO2S terminal D and PCM terminal 2BE^*1 , 2C^*2