Nissan Sentra B18 (2020-2025) Service Manual: Mass Air Flow Sensor

Nissan Sentra B18 (2020-2025) Service Manual / Engine / Work Procedure (After Replacing Electric Throttle Control Actuator) / Component Parts /circuit Diagnosis / Mass Air Flow Sensor

Component Inspection

Component Inspection

CHECK MASS AIR FLOW (MAF) SENSOR-1

With CONSULT

Turn ignition switch OFF.
Reconnect all harness connectors disconnected.
Start the engine and warm it up to normal operating temperature.

Select “MASS AIR FLOW SENSOR (Hz)” in “DATE MONITOR” mode of “ENGINE” using CONSULT and check the indication under the following condition.

Monitor item	Condition	Indication
MASS AIR FLOW SENSOR (Hz)	Ignition switch ON (Engine stopped.)	Approx. 3,700 Hz
	1500 rpm (Engine is warmed-up normal operating temperature)	5,400 - 5,900 Hz
	2500 rpm (Engine is warmed-up normal operating temperature)	5,900 - 6,400 Hz
	4000 rpm (Engine is warmed-up normal operating temperature)	6,400 - 7,200 Hz

Without CONSULT

Turn ignition switch OFF.
Reconnect all harness connectors disconnected.
Start the engine and warm it up to normal operating temperature.

Check the frequency between ECM harness connector terminals under the following conditions.

ECM			Condition	Frequency
Connector	+	−
Connector	Terminal
F24	26	23	Ignition switch ON (Engine stopped.)	Approx. 3,700 Hz
			1500 rpm (Engine is warmed-up normal operating temperature)	5,400 - 5,900 Hz
			2500 rpm (Engine is warmed-up normal operating temperature)	5,900 - 6,400 Hz
			4000 rpm (Engine is warmed-up normal operating temperature)	6,400 - 7,200 Hz

Is the inspection result normal?

YES >>

INSPECTION END

NO >>

GO TO 2.

CHECK FOR THE CAUSE OF UNEVEN AIR FLOW THROUGH INTAKE AIR DUCT
1. Turn ignition switch OFF.
2. Check for the cause of uneven air flow through intake air duct. Refer to the following.
  - Crushed air ducts
  - Malfunctioning seal of air cleaner element
  - Uneven dirt like leaves or insects of air cleaner element
  - Intake valve deposit
  - Improper specification of intake air system parts
Is the inspection result normal?
YES >>
GO TO 4.
NO >>
GO TO 3.

CHECK MAF SENSOR-2

With CONSULT

Repair malfunctioning part.
Start the engine and warm it up to normal operating temperature.

Select “MASS AIR FLOW SENSOR (Hz)” in “DATE MONITOR” mode of “ENGINE” using CONSULT and check the indication under the following condition.

Monitor item	Condition	Indication
MASS AIR FLOW SENSOR (Hz)	Ignition switch ON (Engine stopped.)	Approx. 3,700 Hz
	1500 rpm (Engine is warmed-up normal operating temperature)	5,400 - 5,900 Hz
	2500 rpm (Engine is warmed-up normal operating temperature)	5,900 - 6,400 Hz
	4000 rpm (Engine is warmed-up normal operating temperature)	6,400 - 7,200 Hz

Without CONSULT

Repair malfunctioning part.
Start the engine and warm it up to normal operating temperature.

Check the frequency between ECM harness connector terminals under the following conditions.

ECM			Condition	Frequency
Connector	+	−
Connector	Terminal
F24	26	23	Ignition switch ON (Engine stopped.)	Approx. 3,700 Hz
			1500 rpm (Engine is warmed-up normal operating temperature)	5,400 - 5,900 Hz
			2500 rpm (Engine is warmed-up normal operating temperature)	5,900 - 6,400 Hz
			4000 rpm (Engine is warmed-up normal operating temperature)	6,400 - 7,200 Hz

Is the inspection result normal?

YES >>

INSPECTION END

NO >>

GO TO 4.

CHECK MAF SENSOR-3

With CONSULT

Turn ignition switch OFF.
Reconnect all harness connectors disconnected.
Start the engine and warm it up to normal operating temperature.

Select “MASS AIR FLOW SENSOR (Hz)” in “DATE MONITOR” mode of “ENGINE” using CONSULT and check the indication under the following condition.

Monitor item	Condition	Indication
MASS AIR FLOW SENSOR (Hz)	Ignition switch ON (Engine stopped.)	Approx. 3,700 Hz
	1500 rpm (Engine is warmed-up normal operating temperature)	5,400 - 5,900 Hz
	2500 rpm (Engine is warmed-up normal operating temperature)	5,900 - 6,400 Hz
	4000 rpm (Engine is warmed-up normal operating temperature)	6,400 - 7,200 Hz

Without CONSULT

Turn ignition switch OFF.
Reconnect all harness connectors disconnected.
Start the engine and warm it up to normal operating temperature.

Check the frequency between ECM harness connector terminals under the following conditions.

ECM			Condition	Frequency
Connector	+	−
Connector	Terminal
F24	26	23	Ignition switch ON (Engine stopped.)	Approx. 3,700 Hz
			1500 rpm (Engine is warmed-up normal operating temperature)	5,400 - 5,900 Hz
			2500 rpm (Engine is warmed-up normal operating temperature)	5,900 - 6,400 Hz
			4000 rpm (Engine is warmed-up normal operating temperature)	6,400 - 7,200 Hz

Is the inspection result normal?

YES >>

INSPECTION END

NO >>

Replace MAF sensor. Refer to Exploded View.

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