Air Flow Meter/Sensor: Testing and Inspection

Mass Airflow (MAF)/Intake Air Temperature (IAT) Sensor Inspection


NOTE: Perform the following test only when directed.

MAF Sensor Voltage Inspection

Using the SST (104 pin breakout box)

1. Turn the ignition switch to LOCK.
2. Disconnect the PCM connector.




3. Connect the SST (104 Pin Breakout Box) to the PCM connector and the PCM as shown.
4. Tighten the connector attaching bolt.

Tightening torque
3.0 - 5.4 N.m (30 - 56 kgf.cm, 27 - 48 in.lbf}

5. Turn the ignition switch to ON.
6. Measure the voltage between the breakout box pins 36 and 88.
- If not as specified, perform the "MAF Sensor Circuit Open/Short Inspection".

Specification
0.0 - 0.1 V

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

8. Measure the voltage between the breakout box pins 36 and 88.
- If not as specified, perform the "MAF Sensor Circuit Open/Short Inspection".

Specification
0.5 - 0.8 V

Using the SST (NGS tester)

1. Turn the ignition switch to ON.
2. Set the NGS tester and monitor the MAF V PID.
- If not as specified, perform the "MAF Sensor Circuit Open/Short Inspection".

MAF V PID
0.0 - 0.1 V

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

4. Monitor the MAF V PID.
- If not as specified, perform the "MAF Sensor Circuit Open/Short Inspection".

MAF V PID
0.5 - 0.8 V

MAF Sensor Circuit Open/Short Inspection

1. Disconnect the PCM connector.




2. Connect the SST (104 Pin Breakout Box) with the PCM disconnected.
3. Tighten the connector attaching bolt.

Tightening torque
3.0 - 5.4 N.m (30 - 56 kgf.cm, 27 - 48 in.lbf}




4. 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 D (harness-side)
- MAF/IAT sensor terminal E (harness-side) and 104 pin breakout box terminal 88
- MAF/IAT sensor terminal D (harness-side) and 104 pin breakout box 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 Rate and Load Value

NOTE: The scan tool shows the MAF rate and load value.

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.
- It not as specified, replace the MAF/IAT sensor.
- If the IAT sensor is okay, but the IAT and the IAT V PID are out of specification, perform the "IAT Sensor Circuit Open/Short Inspection".

IAT Sensor Circuit Open/Short Inspection
1. Disconnect the PCM connector.




2. Connect the SST (104 Pin Breakout Box) without connecting to the PCM as shown.
3. Tighten the connector attaching bolt.

Tightening torque
3.0 - 5.4 N.m {30 - 56 kgf.cm, 27 - 48 in.lbf)




4. 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 104 pin breakout box terminal 39
- MAF/IAT sensor terminal F (harness-side) and 104 pin breakout box terminal 91

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