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
Backup Power Supply Inspection: Notes
- Disconnect the negative battery terminal.
- Remove the backup power supply.
- Connect the backup power supply connector.
- Connect the negative battery terminal.
- Verify that the voltages of each of the terminals are as indicated in the terminal voltage table (reference).
- If the voltage is not as specified in the terminal voltage table (reference), inspect the parts under Inspection item(s) and related wiring harnesses.
- If the system does not operate normally even though the inspection items are normal, replace the backup power supply.
- If the voltage is not as specified in the terminal voltage table (reference), inspect the parts under Inspection item(s) and related wiring harnesses.
Factory Service Tools
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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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