Nissan Murano: Dtc/circuit Diagnosis / P0101 Maf Sensor

DTC Description

DTC DETECTION LOGIC

1. A high voltage from the sensor is sent to ECM under light load driving condition.

2. A low voltage from the sensor is sent to ECM under heavy load driving condition.

POSSIBLE CAUSE

• Harness and connectors (The sensor circuit is open or shorted.)

• Intake air leaks

• MAF sensor

• EVAP control system pressure sensor

• Intake air temperature sensor

• Electric throttle control actuator

• PCV hose air leak

• Purge hose air leak

FAIL-SAFE

CHECK DTC PRIORITY

If DTC P0101 is displayed with other DTC, first perform the trouble diagnosis for other DTC.

Is applicable DTC detected?

Perform diagnosis of applicable. Refer to DTC Index.

GO TO 2.

PRECONDITIONING

If DTC CONFIRMATION PROCEDURE has been previously conducted, always perform the following procedure before conducting the next test.

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

2. Turn ignition switch ON.

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

GO TO 3.

PERFORM DTC CONFIRMATION PROCEDURE

1. Start the engine and warm it up to normal operating temperature.

2. Start engine and drive the Nissan Murano vehicle as per the similar conditions to Freeze Frame Data for more than 5 seconds.

   Hold the accelerator pedal as steady as possible.

   CAUTION:

   Always drive Nissan Murano vehicle in safe manner according to traffic conditions and obey all traffic laws when driving.

   • ENGINE SPEED

   • COOLANT TEMP

   • VEHICL SPEED

Is 1st trip DTC detected?

Proceed to Diagnosis Procedure.

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

Confirmation after repair: INSPECTION END

CHECK DTC PRIORITY

If DTC P0101 is displayed with other DTC, first perform the trouble diagnosis for other DTC.

Is applicable DTC detected?

Perform diagnosis of applicable. Refer to DTC Index.

GO TO 2.

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 DTC Confirmation Procedure.

Is 1st trip DTC detected?

GO TO 3.

Inspection End.

CHECK INTAKE SYSTEM

Check the following for connection.

• Air duct

• Vacuum hoses

• Intake air passage between air duct and intake manifold

Is the inspection result normal?

GO TO 4.

Reconnect the parts.

CHECK MASS AIR FLOW (MAF) SENSOR POWER SUPPLY

1. Disconnect MAF sensor harness connector.

2. Ignition switch ON.

3. Check the voltage between MAF sensor harness connector and ground.

   +		−	Voltage (Approx.)
   MAF sensor
   Connector	Terminal
   F94	1	Ground	Approx. 5 V

Is the inspection result normal?

GO TO 6.

GO TO 5.

CHECK MASS AIR FLOW (MAF) SENSOR POWER SUPPLY CIRCUIT

1. Ignition switch OFF.

2. Disconnect ECM harness connector.

3. Check the continuity between MAF sensor harness connector and ECM harness connector.

   MAF sensor		ECM		Continuity
   Connector	Terminal	Connector	Terminal
   F94	1	F78	28	Existed

Is the inspection result normal?

Inspection End.

Repair or replace error-detected parts.

CHECK MAF SENSOR GROUND CIRCUIT

1. Ignition switch OFF.

2. Disconnect ECM harness connector.

3. Check the continuity between MAF sensor harness connector and ECM harness connector.

   MAF sensor		ECM		Continuity
   Connector	Terminal	Connector	Terminal
   F94	3	F78	40	Existed

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

Is the inspection result normal?

GO TO 7.

Repair open circuit or short to ground or short to power in harness or connectors.

CHECK MAF SENSOR INPUT SIGNAL CIRCUIT

1. Check the continuity between MAF sensor harness connector and ECM harness connector.

   MAF sensor		ECM		Continuity
   Connector	Terminal	Connector	Terminal
   F94	2	F78	38	Existed

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

Is the inspection result normal?

GO TO 8.

Repair open circuit or short to ground or short to power in harness or connectors.

CHECK INTAKE AIR TEMPERATURE SENSOR

Check intake air temperature sensor. Refer to Component Inspection.

Is the inspection result normal?

GO TO 9.

Replace MAF sensor (with intake air temperature sensor).

CHECK PCV VALVE

Check the PCV valve. Refer to Work Procedure .

Is the inspection result normal?

GO TO 10.

Replace PCV valve.

CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR

Check EVAP control system pressure sensor. Refer to Component Inspection.

Is the inspection result normal?

GO TO 11.

Replace EVAP control system pressure sensor.

PERFORM EVAP LEAK CHECK

Perform the EVAP leak check. Refer to Component Inspection .

GO TO 12.

CHECK THROTTLE POSITION SENSOR

Check the followings with the freeze frame data of DTC P0101

Is the freeze frame data under the above condition?

Perform idle air volume learning. Refer to Description.

GO TO 13.

CHECK MAF SENSOR

Check MAF sensor. Refer to Component Inspection.

Is the inspection result normal?

Inspection End.

Replace MAF sensor. Refer to Removal and Installation.

CHECK MASS AIR FLOW (MAF) SENSOR-I

With CONSULT

1. Turn ignition switch OFF.

2. Reconnect all harness connectors disconnected.

3. Start engine and warm it up to normal operating temperature.

4. Connect CONSULT and select “DATA MONITOR” mode.

5. Select “MASS AIR FLOW SENSOR (Hz)” and check the indication.

   Monitor item	Condition	Indication (Hz)
   MASS AIR FLOW SENSOR (Hz)	Ignition switch ON (Engine stopped.)	Approx. 3,720 Hz
   	Idle (Engine is warmed-up to normal operating temperature.)	4,000 - 4,300 Hz
   	Idle to about 4,000 rpm	4,000 - 4,300 to Approx. 8,000 Hz*

   *: Check for linear frequency rise in response to engine being increased to about 4,000 rpm.

Without CONSULT

1. Turn ignition switch OFF.

2. Reconnect all harness connectors disconnected.

3. Start engine and warm it up to normal operating temperature.

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

   ECM			Condition	Frequency (Hz)
   Connector	+	–
   	Terminal
   F78	38	40	Ignition switch ON (Engine stopped.)	Approx. 3,720 Hz
   			Idle (Engine is warmed-up to normal operating temperature.)	4,000 - 4,300 Hz
   			Idle to about 4,000 rpm	4,000 - 4,300 to Approx. 8,000 Hz*

   *: Check for linear frequency rise in response to engine being increased to about 4,000 rpm.

Is the inspection result normal?

GO TO 4.

GO TO 2.

CHECK FOR THE CAUSE OF UNEVEN AIR FLOW THROUGH MAF SENSOR

1. Turn ignition switch OFF.

2. Check for the cause of uneven air flow through MAF sensor. Refer to the following.

   • Crushed air ducts

   • Malfunctioning seal of air cleaner element

   • Uneven dirt of air cleaner element

   • Improper specification of intake air system parts

Is the inspection result normal?

GO TO 4.

GO TO 3.

CHECK MAF SENSOR-II

With CONSULT

1. Repair or replace malfunctioning part.

2. Start engine and warm it up to normal operating temperature.

3. Connect CONSULT and select “DATA MONITOR” mode.

4. Select “MASS AIR FLOW SENSOR (Hz)” and check the indication.

   Monitor item	Condition	Indication (Hz)
   MASS AIR FLOW SENSOR (Hz)	Ignition switch ON (Engine stopped.)	Approx. 3,720 Hz
   	Idle (Engine is warmed-up to normal operating temperature.)	4,000 - 4,3000 Hz
   	Idle to about 4,000 rpm	4,000 - 4,300 to Approx. 8,000 Hz*

   *: Check for linear frequency rise in response to engine being increased to about 4,000 rpm.

Without CONSULT

1. Repair or replace malfunctioning part.

2. Start engine and warm it up to normal operating temperature.

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

   ECM			Condition	Frequency (Hz)
   Connector	+	–
   	Terminal
   F78	38	40	Ignition switch ON (Engine stopped.)	Approx. 3,720 Hz
   			Idle (Engine is warmed-up to normal operating temperature.)	4,000 - 4,300 Hz
   			Idle to about 4,000 rpm	4,000 - 4,300 to Approx. 8,000 Hz*

   *: Check for linear frequency rise in response to engine being increased to about 4,000 rpm.

Is the inspection result normal?

INSPECTION END

GO TO 4.

CHECK MAF SENSOR-III

With CONSULT

1. Turn ignition switch OFF.

2. Disconnect MAF sensor harness connector and reconnect it again.

3. Start engine and warm it up to normal operating temperature.

4. Connect CONSULT and select “DATA MONITOR” mode.

5. Select “MASS AIR FLOW SENSOR (Hz)” and check the indication.

   Monitor item	Condition	Indication (Hz)
   MASS AIR FLOW SENSOR (Hz)	Ignition switch ON (Engine stopped.)	Approx. 3,720 Hz
   	Idle (Engine is warmed-up to normal operating temperature.)	4,000 - 4,300 Hz
   	Idle to about 4,000 rpm	4,000 - 4,300 to Approx. 8,000 Hz*

   *: Check for linear frequency rise in response to engine being increased to about 4,000 rpm.

Without CONSULT

1. Turn ignition switch OFF.

2. Disconnect MAF sensor harness connector and reconnect it again.

3. Start engine and warm it up to normal operating temperature.

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

   ECM			Condition	Frequency (Hz)
   Connector	+	–
   	Terminal
   F78	38	40	Ignition switch ON (Engine stopped.)	Approx. 3,720 Hz
   			Idle (Engine is warmed-up to normal operating temperature.)	4,000 - 4,300 Hz
   			Idle to about 4,000 rpm	4,000 - 4,300 to Approx. 8,000 Hz*

   *: Check for linear frequency rise in response to engine being increased to about 4,000 rpm.

Is the inspection result normal?

INSPECTION END

Clean or replace MAF sensor. Refer to Removal and Installation.