Short circuit

If there is continuity in the following wiring harnesses, there is a short circuit. Repair or replace the wiring harness.
- Front HO2S terminal A and body ground
- Front HO2S terminal A and power supply
- Front HO2S terminal B and body ground
- Front HO2S terminal B and power supply
- Front HO2S terminal C and body ground
- Front HO2S terminal C and power supply
- Front HO2S terminal D and body ground

If there is continuity, there is a short circuit. Repair or replace the wiring harness.
- Middle/rear HO2S terminal A and body ground
- Middle/rear HO2S terminal A and power supply
- Middle/rear HO2S terminal B and power supply
  
  Fig 1: PCM Connector Terminal Identification
  Courtesy of MAZDA MOTORS CORP.

If there is no continuity, there is a short circuit. Repair or replace the wiring harness.
Middle and rear
- Middle/rear HO2S terminal C and body ground
- Middle/rear HO2S terminal D and power supply
- Middle/rear HO2S terminal D and body ground
  
  Fig 1: PCM Connector Terminal Identification
  Courtesy of MAZDA MOTORS CORP.