Detection Condition

WARNING: This page is about a different car, the 2003 Mazda 6. However, it is still accessible from the selected car via links, so may be relevant.

PCM monitors inversion cycle period, lean-to-rich response time and rich-to-lean response time of the sensor. PCM calculates average of inversion cycle period-specified inversion cycles, average response time from lean-to-rich, and from rich-to-lean when following monitoring conditions are met. If any exceeds the threshold, PCM determines circuit has a malfunction.

Monitoring Conditions:

Drive mode 3
Following conditions are to be met:
1. Calculation load: 18-58 percent, depending on engine speed.
2. Engine speed: 1400-2500 RPM (MTX)
3. Engine speed: 1200-2500 RPM (ATX)
4. Engine coolant temperature: 14°F (-10°C) or more

This is an intermittent monitor (O2 sensor). MIL illuminates if PCM detects malfunction condition in two consecutive drive cycles or in one drive cycle while DTC for same malfunction has been stored in PCM. PENDING CODE is available if PCM detects malfunction condition during first drive cycle. FREEZE FRAME DATA is available. DTC is stored in PCM memory.