MASS AIR FLOW (MAF)/INTAKE AIR TEMPERATURE (IAT) SENSOR INSPECTION [AJ] (VIN: JMZ LW19J7*# 300001-, JM0 LW10J300 300001-301405, JM6 LW10J300 300001-, JM8 LW28J**# 300001-301513)


BME014013215203

Note
• Perform the following test only when directed.

MAF Sensor Voltage Inspection

1. Turn the ignition switch to LOCK.

2. Connect the WDS or equivalent to the DLC-2.

3. Turn the ignition switch to ON position (Engine OFF).

4. Select MAF PID on the WDS or equivalent.

5. Verify that MAF PID is within the specification.

• If not as specified, perform the "MAF Sensor Circuit Open/Short Inspection".
Specification
0.0-0.1 V

6. Turn the ignition switch to START and warm up the engine completely.

7. Verify that MAF PID is within the specification.

• If not as specified, perform the "MAF Sensor Circuit Open/Short Inspection".
Specification
0.5-0.8 V

MAF Sensor Circuit Open/Short Inspection

1. Disconnect the PCM connector. (See PCM REMOVAL/INSTALLATION [AJ].)

2. Inspect the following wiring harness for open or short (Continuity check).

Open circuit

• If there is no continuity, the circuit is open. Repair or replace the harness.
- MAF/IAT sensor terminal B (harness-side) and main relay terminal C (harness-side)
- MAF/IAT sensor terminal E (harness-side) and PCM terminal 88
- MAF/IAT sensor terminal D (harness-side) and PCM terminal 36

Short circuit

• If there is continuity, the circuit is shorted. Repair or replace the harness.
- MAF/IAT sensor terminal B (harness-side) and body ground
- MAF/IAT sensor terminal E (harness-side) and power supply
- MAF/IAT sensor terminal E (harness-side) and body ground
- MAF/IAT sensor terminal D (harness-side) and power supply
- MAF/IAT sensor terminal D (harness-side) and body ground

MAF Rate and Load Value

Note
• The scan tool shows the MAF rate and load value.

Specification

item

Intake MAF (g/s)

Engine load calculated value (%)

Idle*1
3.3-4.7
18-20
Engine speed 2,500 rpm*2
12.1-15.0
17-19

*1 :
700-800 rpm
*2 :
No load, N position or P position

IAT Sensor Resistance Inspection

1. Disconnect the MAF/IAT sensor connector.

2. Measure the resistance between MAF/IAT sensor terminals A and F using an ohmmeter.

• If not as specified, replace the MAF/IAT sensor.
• If the IAT sensor is normal, but the IAT PID is out of specification, perform the "IAT Sensor Circuit Open/Short Inspection".

Specification

Ambient temperature (°C {°F})

Resistance (kilohms)

10 {50}
3.3-4.1
20 {68}
2.2-2.7
30 {86}
1.4-1.9

IAT Sensor Circuit Open/Short Inspection

1. Disconnect the PCM connector. (See PCM REMOVAL/INSTALLATION [AJ].)

2. Inspect the following wiring harness for open or short (Continuity check).

Open circuit

• If there is no continuity, the circuit is open. Repair or replace the harness.
- MAF/IAT sensor terminal A (harness-side) and PCM terminal 91
- MAF/IAT sensor terminal F (harness-side) and PCM terminal 39

Short circuit

• If there is continuity, the circuit is shorted. Repair or replace the harness.
- MAF/IAT sensor terminal A (harness-side) and power supply
- MAF/IAT sensor terminal F (harness-side) and power supply
- MAF/IAT sensor terminal F (harness-side) and body ground