Detection Condition
WARNING: This page is about a different car, the 2003 Mazda Protege5 and 2003 Mazda Protege. However, it is still accessible from the selected car via links, so may be relevant.
DTC is set when PCM detects low input voltage from control circuit of rear HO2S heater after PCM turns HO2S heater off. This is an intermittent monitor. MIL is illuminated when PCM detects malfunction condition in 2 consecutive drive cycles. Pending code is available if PCM detects malfunction condition during first drive cycle. Freeze frame data is available and DTC is stored in PCM memory.