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.
2021 Mazda 3 BaseFACTORY OEM SERVICE PROCEDURE
Front Ultrasonic Sensor Inspection
NOTE:
- The integrity of the front ultrasonic sensor cannot be determined from a single part. When inspecting the front ultrasonic sensor, perform the following procedure.
- Connect the M-MDS to the DLC-2.
- Perform the DTC inspection for the parking assist unit (ultrasonic) and verify if any DTCs related to the front ultrasonic sensor is detected. (See DTC INSPECTION
.)
- If DTCs are detected, repair the malfunctioning location according to the applicable DTC troubleshooting. (See DTC TABLE [PARKING ASSIST UNIT (ULTRASONIC) (US)] .)
- If DTCs are not detected, repair the malfunctioning location according to the symptom troubleshooting. (See SYMPTOM TROUBLESHOOTING [PARKING ASSIST SYSTEM] .)
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.
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