MASS AIR FLOW (MAF) SENSOR INSPECTION [L3 Turbo]

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Visual Inspection

Note

• Before performing the following inspection, make sure to follow the procedure as indicated in the troubleshooting flowchart. (See HOW TO USE THIS MANUAL.)

1. Visually inspect for the following on the MAF sensor. (SeeINTAKE-AIR SYSTEM REMOVAL/INSTALLATION [L3 Turbo].)

• Damage

• Cracks

• Bent terminals

• Terminal rust

― If any of the above are found, replace the MAF/IAT sensor. (SeeINTAKE-AIR SYSTEM REMOVAL/INSTALLATION [L3 Turbo].)

― If the monitor item status/specification (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 the ON position.

3. As the air gradually approaches the MAF detection part of the MAF/IAT sensor, verify that the voltage at PCM terminal 1AK (M-MDS PID: MAF) varies. (SeePCM INSPECTION [L3 Turbo].)

• If it cannot be verified even though the related harnesses have no malfunction, replace the MAF/IAT sensor. (SeeINTAKE-AIR SYSTEM REMOVAL/INSTALLATION [L3 Turbo].)

Circuit Open/Short Inspection

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1. Disconnect the PCM connector. (SeePCM REMOVAL/INSTALLATION [L3 Turbo].)

2. Disconnect the MAF/IAT sensor connector.

3. Inspect the following wiring harnesses for an open or short circuit. (Continuity check)

Open circuit

• If there is no continuity, there is an open circuit. Repair or replace the wiring harness.

― MAF/IAT sensor terminal A and main relay terminal E

― MAF/IAT sensor terminal B and PCM terminal 1P

― MAF/IAT sensor terminal C and PCM terminal 1AK

Short circuit

• If there is continuity, there is a short circuit. Repair or replace the wiring harness.

― MAF/IAT sensor terminal A and body ground

― MAF/IAT sensor terminal B and power supply

― MAF/IAT sensor terminal C and power supply

― MAF/IAT sensor terminal C and body ground