1. When the monitor is turned on, it will automatically communicate with the DPU. Once the DPU detects a wide band oxygen signal, the screen will automatically display the Wide Band Oxygen version; If no wide band oxygen signal is detected, the screen will automatically display the Narrow Band Oxygen version.

Under Wide Band oxygen version, the "air-fuel ratio" parameter on the screen displays the air-fuel ratio data detected by the wide oxygen sensor, with the display range of 0.0 ~ 99.9:1. At the same time, two additional parameters will appear in the multi-function display area at the bottom: LAMBDA (λ) and OXYGEN (the percentage of oxygen content).

Under Narrow Band oxygen version: When the system does not detect a wide band oxygen signal, the "air-fuel ratio" parameter on the screen displays the air-fuel ratio data of the narrow band oxygen sensor, and the display range is 20 ~ 10:1.

2. When the wide oxygen sensor is working, the controller will monitor its status at all times. Once an error is found, the controller will stop monitoring the wide oxygen sensor and display the error code "ERR xx" in the multi-function display area at the bottom of the screen.

("xx" represents the specific error code. For example, when working normally, unplug the sensor wiring, and the instrument displays "Err 7F")

When the wide oxygen sensor starts to work, there is a pre-heating process of about 1–2 minutes. At this time, the air fuel ratio on the screen will display 0.00, which is a normal display. When the sensor enters the normal state, the correct air fuel ratio value will be displayed.