Nissan Sentra B18 (2020-2025) Service Manual: P0102 Maf Sensor

Dtc Description

DTC DETECTION LOGIC

POSSIBLE CAUSE

• Harness or connectors [The mass air flow sensor (bank 1) circuit is open or shorted.]

• Intake air leaks

• Mass air flow sensor

FAIL-SAFE

Engine Control System

Engine operating condition in fail-safe mode
Fail safe mode		Nissan Sentra Vehicle behavior
Traveling control mode	Accelerator angle variation control	ECM controls the accelerator pedal depression speed to make it slower than actual speed. This causes a drop in accelerating performance and encourages the driver to repair malfunction. Note: ECM does not control the accelerator pedal releasing speed.
	Engine output control 1	ECM reduces the engine output, according to the rise in engine speed. This reduces the Nissan Sentra vehicle speed to encourage the driver to repair malfunction. Driving at 70 km/h (44 MPH) or more is possible. Note: This value is a reference value converted from engine power to Nissan Sentra vehicle speed. Actual power limitation value differs due to the malfunctioning part and driving condition.
Device fix mode		This mode fixes the electric IVT motor and the EVT control solenoid valve in the reference position. The intake manifold runner control valve motor is turned OFF (intake manifold runner control valve opens).
Combustion control mode	Stratified charge combustion control at starting	No stratified charge combustion at starting (cold start).
	Idle speed control	Stops feedback control of idle speed and controls with specified speed.
	Recovery speed control at decelerating	Stops recovery speed control by the fuel cut at decelerating and controls with specified speed.
	Idle neutral control	Stops idle neutral control.
	Ignition timing correction control	Partially controls ignition timing control.
	Retardation control	Controls ignition timing delay control in the intermediate water temperature range.

Idle Start/Stop System

When a DTC is detected, the start/stop indicator lamp blinks slowly and the idle start/stop system operation is prohibited.

When ECM detects error while operating the idle start/stop system, ECM restarts the engine.

Confirmation Procedure

1. PRECONDITIONING

   If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at least 10 seconds before conducting the next test.

   Which DTC is detected?

   P0102>>

   GO TO 2.

   P0103>>

   GO TO 3.

2. DTC CONFIRMATION PROCEDURE-DTC P0102

   1. Start the engine and let it idle at least 5 seconds.

   2. Check DTC.

   Is DTC detected?

   YES >>

   Proceed to DTC Diagnosis Procedure.

   NO >>

   INSPECTION END

3. DTC CONFIRMATION PROCEDURE-DTC P0103-1

   1. Turn ignition switch ON and wait at least 5 seconds.

   2. Check DTC.

   Is DTC detected?

   YES >>

   Proceed to DTC Diagnosis Procedure.

   NO >>

   GO TO 4.

4. DTC CONFIRMATION PROCEDURE-DTC P0103-2

   1. Turn ignition switch OFF and wait at least 10 seconds.

   2. Start the engine and let it idle at least 5 seconds.

   3. Check DTC.

   Is DTC detected?

   YES >>

   Proceed to DTC Diagnosis Procedure.

   NO-1 >>

   To check malfunction symptom before repair: Refer to Intermittent Incident.

   NO-2 >>

   Confirmation after repair: INSPECTION END

Dtc Diagnosis Procedure

1. CHECK HARNESS CONNECTOR

   1. Disconnect MAF sensor harness connector and ECM harness connector.

   2. Connect MAF sensor harness connector and ECM harness connector.

   3. Perform DTC Confirmation Procedure. Refer to Confirmation Procedure.

   Is DTC detected?

   YES >>

   GO TO 2.

   NO >>

   INSPECTION END

2. CHECK INTAKE SYSTEM

   Check the following for connection.

   • Air duct

   • Vacuum hoses

   • Intake air passage between air duct to intake manifold

   Is the inspection result normal?

   YES >>

   GO TO 3.

   NO >>

   Reconnect the parts.

3. CHECK MASS AIR FLOW SENSOR POWER SUPPLY

   1. Turn ignition switch OFF.

   2. Disconnect mass air flow (MAF) sensor harness connector.

   3. Turn ignition switch ON.

   4. Check the voltage between mass air flow (MAF) sensor harness connector and ground.

      +		Ground	Voltage (Approx.)
      MAF sensor
      Connector	Terminal
      F31	1	Ground	5.0 V

   Is the inspection result normal?

   YES >>

   GO TO 4.

   NO >>

   Repair or replace malfunctioning part.

4. CHECK MASS AIR FLOW SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT

   1. Check the continuity between mass air flow (MAF) sensor harness connector and ECM harness connector.

      MAF sensor		ECM		Continuity
      Connector	Terminal	Connector	Terminal
      F31	2	F24	26	Existed

   2. Also check harness for short to ground and short to power.

   Is the inspection result normal?

   YES >>

   GO TO 5.

   NO >>

   Repair or replace malfunctioning part.

5. CHECK INTAKE AIR TEMPERATURE SENSOR

   Refer to Component Inspection.

   Is the inspection result normal?

   YES >>

   GO TO 6.

   NO >>

   Replace mass air flow (MAF) sensor (with intake air temperature sensor). Refer to Exploded View.

6. CHECK MASS AIR FLOW SENSOR

   Refer to Component Inspection.

   Is the inspection result normal?

   YES >>

   INSPECTION END

   NO >>

   Replace mass air flow (MAF) sensor. Refer to Exploded View.

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