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.
2004 Mazda RX8 2RTR-1.3LFACTORY OEM SERVICE PROCEDURE
Air Flow Meter/Sensor: Testing and Inspection
MASS AIR FLOW (MAF) SENSOR INSPECTION
NOTE: Before performing the following inspection, make sure to follow the troubleshooting flowchart. (See FOREWORD.) Flow of Diagnosis
Visual Inspection
1. Visually inspect the MAF/IAT sensor for the following:
- Damage, cracks
- Rusted sensor terminal
- Bent sensor terminal
- If there is any malfunction, replace the MAF/IAT sensor.
- If the monitor item condition (reference) is not within the specification even though there is no malfunction, perform the "Circuit Open/Short Inspection".
Voltage Inspection
1. Remove the MAF/IAT sensor without disconnect the MAF/IAT sensor connector.
2. Turn the ignition switch to ON position.
3. As the air gradually approaches the MAF detection part of the MAF/IAT sensor, verify that the voltage at PCM terminal 5N (WDS PID: MAF) varies.
- If it cannot be verified even though the related harnesses have no malfunction, replace the MAF/IAT sensor.
Circuit Open/Short Inspection
1. Disconnect the PCM connector.
2. Disconnect the MAF/IAT sensor connector.
3. Inspect the following wiring harnesses for open or short circuit. (Continuity inspection)
Open circuit
- If there is no continuity in the following wiring harnesses, there is an open circuit. Repair or replace the wiring harness.
- MAF/IAT sensor terminal A and main relay terminal C
- MAF/IAT sensor terminal B and PCM terminal 5U
- MAF/IAT sensor terminal C and PCM terminal 5N
Short circuit
- If there is continuity in the following wiring harnesses, there is a short circuit. Repair or replace the wiring harness.
- MAF/IAT sensor terminal A and body ground
- MAF/IAT sensor terminal C and power supply
- MAF/IAT sensor terminal C and body ground
NOTE: Before performing the following inspection, make sure to follow the troubleshooting flowchart. (See FOREWORD.) Flow of Diagnosis
Visual Inspection
1. Visually inspect the MAF/IAT sensor for the following:
- Damage, cracks
- Rusted sensor terminal
- Bent sensor terminal
- If there is any malfunction, replace the MAF/IAT sensor.
- If the monitor item condition (reference) is not within the specification even though there is no malfunction, perform the "Circuit Open/Short Inspection".
Voltage Inspection
1. Remove the MAF/IAT sensor without disconnect the MAF/IAT sensor connector.
2. Turn the ignition switch to ON position.
3. As the air gradually approaches the MAF detection part of the MAF/IAT sensor, verify that the voltage at PCM terminal 5N (WDS PID: MAF) varies.
- If it cannot be verified even though the related harnesses have no malfunction, replace the MAF/IAT sensor.
Circuit Open/Short Inspection
1. Disconnect the PCM connector.
2. Disconnect the MAF/IAT sensor connector.
3. Inspect the following wiring harnesses for open or short circuit. (Continuity inspection)
Open circuit
- If there is no continuity in the following wiring harnesses, there is an open circuit. Repair or replace the wiring harness.
- MAF/IAT sensor terminal A and main relay terminal C
- MAF/IAT sensor terminal B and PCM terminal 5U
- MAF/IAT sensor terminal C and PCM terminal 5N
Short circuit
- If there is continuity in the following wiring harnesses, there is a short circuit. Repair or replace the wiring harness.
- MAF/IAT sensor terminal A and body ground
- MAF/IAT sensor terminal C and power supply
- MAF/IAT sensor terminal C and body ground
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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