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
Security And Locks-Related Parts Programming
- Connect the M-MDS to the DLC-2.
- Switch the ignition ON (engine off).
- Activate the M-MDS and perform the following procedure.
- Press [Start] to start the vehicle identification.
- Press the [Toolbox] tab.
- Press the [Work Support] icon.
- Press [SECURITY AND LOCKS].
- Select the following items according to the maintenance contents.
M-MDS Service content IMMOBILIZER Select when programming immobilizer system-related parts. (See IMMOBILIZER SYSTEM-RELATED PARTS PROGRAMMING [(US)] .) Registering Key Fob for Remote Engine Starter Select when programming the remote engine starter (key type). Disabling Keyless radio waves to protect pacemakers Select when enabling the pacemaker radio interference prevention function. Resuming keyless radio waves to activate all functions Select when disabling the pacemaker radio interference prevention function. - Perform security and lock related programming according to the M-MDS screen instructions.
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.