A/F Sensor Inspection

WARNING: This page is about a different car, the 2020 Mazda CX-30. However, it is still accessible from the selected car via links, so may be relevant.

Connect the M-MDS to the DLC-2.
Switch the ignition ON (engine on).
Warm up the engine to normal operating temperature.
Access the following PIDs using the M-MDS. (See PID/DATA MONITOR INSPECTION .)
- VSS (Vehicle speed)
- ENG_RPM (Engine speed)
- A/F_SEN_CUR (A/F sensor output current)
Drive the vehicle and decelerate the engine speed by releasing the accelerator pedal fully when the engine speed is 3, 000 rpm or more.
Verify that the A/F sensor output current (PID: A/F_SEN_CUR) is 0.25 mA or more while decelerating as shown in the illustration.

Courtesy of MAZDA MOTORS CORP.

If not as specified, replace the A/F sensor. (See AIR FUEL RATIO (A/F) SENSOR REMOVAL/INSTALLATION .)