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With CONSULT-II

Reconnect all harness connectors disconnected.
Start engine and warm it up to normal operating temperature.
Connect CONSULT-II and select "DATA MONITOR" mode.

Select "MAS A/F SE-B1" and check indication under the following conditions.

Fig 1: Checking Voltage Between ECM Terminal & Ground

G02388648

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

VOLTAGE CONDITION

Condition

MAS A/F SE-B1 (V)

Ignition switch ON (Engine stopped.)

Approx. 0.4

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

1.0 - 1.3

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

1.7 - 2.1

Idle to about 4,000 RPM ⁽¹⁾

1.0 - 1.3 to Approx. 2.4

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

If the voltage is out of specification, proceed the following.
1. Check for the cause of uneven air flow through mass air flow sensor. Refer to following.
  - Crushed air ducts
  - Malfunctioning seal of air cleaner element
  - Uneven dirt of air cleaner element
  - Improper specification of intake air system parts
2. If NG, repair or replace malfunctioning part and perform step 2 to 4 again.
  If OK, go to next step.
Turn ignition switch OFF.
Disconnect mass air flow sensor harness connector and reconnect it again.
Perform step 2 to 4 again.
If NG, clean or replace mass air flow sensor.