Mass Air Flow Sensor

WARNING: This page is about a different car, the 2004 Infiniti FX45. However, it is still accessible from the selected car via links, so may be relevant.

Reconnect all harness connectors disconnected.
Start engine and warm it up to normal operating temperature.
Check voltage between ECM terminal 51 (Mass air flow sensor signal) and ground.

Fig 1: Mass Air Flow Sensor Signal Testing Conditions
Courtesy of NISSAN MOTOR CO., U.S.A.

Fig 2: Testing Mass Air Flow Sensor Signal
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 film for damage or dust.
If NG, clean or replace mass air flow sensor.