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
Function Inspection
WARNING: This page is about a different variant/trim than selected.
- Connect the M-MDS to the DLC-2.
- Switch the ignition ON (engine off).
- Display the PCM PID [BOOST_PRES_ACT] and [BOOST_PRES_ACT_VOLT]. (See PID/DATA MONITOR INSPECTION .) (See PID/DATA MONITOR TABLE [PCM (VIN Y)] .)
- Compare the voltage and boost pressure indications for the PIDs [BOOST_PRES_ACT_VOLT] and [BOOST_PRES_ACT] with the standard in the table indicated below.
- If they do not match the standard, perform the voltage inspection. (See VOLTAGE INSPECTION .)
STANDARD VOLTAGE SPECIFICATION
| BOOST_PRES_ACT_VOLT | BOOST_PRES_ACT | Remarks |
|---|---|---|
| V | kPa {kgf/cm2 , psi} | |
| Approx. 4.12 | 101 {1.03, 14.6} | Ignition switched ON (engine off) |
| Approx. 1.90 | 33 {0.34, 4.8} | Idle (after warm up) |
| Approx. 1.23 | 26 {0.27, 3.8} | Racing (Engine speed: 2, 000 rpm) |
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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