Mass Air Flow (MAF) Sensor Inspection

NOTE:

The MAF sensor and IAT sensor cannot be removed as a single unit. When replacing the MAF sensor or IAT sensor, replace it together with the MAF/IAT sensor as a single unit.

Verify the connection condition of the MAF sensor/IAT sensor connector.
- If a connector has poor contact, install it correctly and then go to the next step.
- If the connector connection is normal, go to the next step.
Verify the MAF sensor voltage under no airflow conditions using the following procedure:
- Connect the M-MDS to the DLC-2.
  CAUTION:
  - Do not create suction in the exhaust pipe by cranking the engine and causing air to flow through the exhaust duct. It could cause a measurement error because the MAF sensor voltage is measured under no airflow conditions.
- Switch the ignition to ON (engine off) and wait for 30 s.
- Verify that the MAF/IAT sensor output voltage (PID: MAF).
Specification
- 0.68 V
- If it is the specification or more, replace the MAF/IAT sensor. (See INTAKE-AIR SYSTEM REMOVAL/INSTALLATION .)
- If it is less than the specification, go to the next step.
Remove the MAF/IAT sensor. (See INTAKE-AIR SYSTEM REMOVAL/INSTALLATION .)
Verify that there is no foreign matter in the MAF/IAT sensor.
- Shine light on the sensor (Direction A in figure below) in the flow path and verify visually.
  - If there is visible, large foreign matter, replace the MAF/IAT sensor. (See INTAKE-AIR SYSTEM REMOVAL/INSTALLATION .)
  - If there is no foreign matter, go to the next step.
    
    Fig 1: Inspecting Sensor For Foreign Matter
Verify that there is no damage, cracks, or dirt on the MAF sensor part of the MAD/IAT sensor.
- If a malfunction can be verified, repair or replace the MAF/IAT sensor. (See INTAKE-AIR SYSTEM REMOVAL/INSTALLATION .)
- If a malfunction cannot be verified, go to the next step (MAF sensor is normal).
NOTE:
- Install the removed MAF/IAT sensor because the MAF sensor is normal.
Install the MAF/IAT sensor. (See INTAKE-AIR SYSTEM REMOVAL/INSTALLATION .)