Mass Air Flow Sensor

Check voltage between ECM terminal 51 (Mass air flow sensor signal) and ground.

VOLTAGE CHECKING CONDITION

Condition

Voltage V

Ignition switch ON (Engine stopped.)

Approx. 0.4

Idle (Engine is warmed-up to normal operating temperature.)

1.1 - 1.4

2,500 RPM (Engine is warmed-up to normal operating temperature.)

1.7 - 2.0

Idle to about 4,000 RPM⁽¹⁾

1.1 - 1.4 to Approx. 4.0

⁽¹⁾	Check for linear voltage rise in response to engine being increased to about 4,000 RPM.

Fig 1: Checking Voltage Between ECM Terminal & Ground

Courtesy of NISSAN MOTOR CO., U.S.A.

If the voltage is out of specification, proceed the following.
- Turn ignition switch OFF.
- Disconnect mass air flow sensor harness connector and reconnect it again.
- Perform steps 2 and 3 again.
If NG, remove mass air flow sensor from air duct. Check hot wire for damage or dust.
If NG, clean or replace mass air flow sensor.