Open Circuit

WARNING: This page is about a different car, the 2004 Mazda 6. However, it is still accessible from the selected car via links, so may be relevant.

HO2S (RF) terminal C (harness-side) and ignition switch
HO2S (RF) terminal D (harness-side) and PCM terminal 93 (harness-side)
HO2S (LF) terminal C (harness-side) and ignition switch
HO2S (LF) terminal D (harness-side) and PCM terminal 94 (harness-side)
HO2S (RR) terminal C (harness-side) and ignition switch
HO2S (RR) terminal D (harness-side) and PCM terminal 95 (harness-side)
HO2S (LR) terminal C (harness-side) and ignition switch
HO2S (LR) terminal D (harness-side) and PCM terminal 96 (harness-side)