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