Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
2020 Mazda CX-30 Base, AWDFACTORY OEM SERVICE PROCEDURE
HO2S Inspection
- 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)
- HO2S_OUT_VOLT (HO2S output voltage)
- 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 HO2S output voltage (PID: HO2S_OUT_VOLT) is 0.3 V or less while decelerating as shown in the illustration.
- If not as specified, replace the HO2S. (See HEATED OXYGEN SENSOR (HO2S) REMOVAL/INSTALLATION .)
Factory Service Tools
Use the Manual With the Right Hardware
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.