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
PCM terminals
WARNING: This page is about a different variant/trim than selected.
- IGT1 (ignition coil No. 1): 1BC (+)-body ground (-)
- IGT2 (ignition coil No. 2): 1BI (+)-body ground (-)
- IGT3 (ignition coil No. 3): 1BO (+)-body ground (-)
- IGT4 (ignition coil No. 4): 1BU (+)-body ground (-)
Oscilloscope setting
- 2 V/DIV (Y), 20 ms/DIV (X), DC range
Vehicle condition
- Idle after warm up
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.