This article show the mini guide on how to use OBDSTAR X300 DP PAD to diagnose Mazda 3,check the pics to get info you want:
Power on the OBDSTAR X300 DP PAD,select “Diag Program”
Select “OBDII”
Press “OK”
Select “AUTO SCAN”,the select “OK”
Select “Read Codes”
Select “Stored Codes”,then press “OK”
And other show as below pic