MASS AIR FLOW (MAF) SENSOR INSPECTION

BHE014013215W02

Note

• Before performing the following inspection, make sure to follow the troubleshooting flowchart. (See Troubleshooting Procedure.)

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. (See MASS AIR FLOW (MAF)/INTAKE AIR TEMPERATURE (IAT) SENSOR REMOVAL/INSTALLATION.)

– 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. (See MASS AIR FLOW (MAF)/INTAKE AIR TEMPERATURE (IAT) SENSOR REMOVAL/INSTALLATION.)

AT

Engine speed

Engine load calculated value (WDS PID: LOAD)

Intake MAF (WDS PID: MAF)

Idle after warm-up (no load)

20-28%

4.4-5.3 g/s

2,500 rpm

15.0-21.0%

9.5-12.5 g/s

Engine speed	Engine load calculated value (WDS PID: LOAD)	Intake MAF (WDS PID: MAF)
Idle after warm-up (no load)	20-28%	4.4-5.3 g/s
2,500 rpm	15.0-21.0%	9.5-12.5 g/s

MT

Engine speed

Engine load calculated value (WDS PID: LOAD)

Intake MAF (WDS PID: MAF)

Idle after warm-up (no load)

18.0-25.0%

3.8-4.7 g/s

2,500 rpm

13.5-19.5%

8.7-11.7 g/s

Engine speed	Engine load calculated value (WDS PID: LOAD)	Intake MAF (WDS PID: MAF)
Idle after warm-up (no load)	18.0-25.0%	3.8-4.7 g/s
2,500 rpm	13.5-19.5%	8.7-11.7 g/s

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