Operation CHARM: Car repair manuals for everyone.

P0101




P0101, P010B MAF SENSOR

Description






The mass air flow sensor (1) is placed in the stream of intake air. It measures the intake flow rate by measuring a part of the entire intake flow. The mass air flow sensor controls the temperature of the hot wire to a certain amount. The heat generated by the hot wire is reduced as the intake air flows around it. The more air, the greater the heat loss.
Therefore, the electric current supplied to hot wire is changed to maintain the temperature of the hot wire as air flow increases. The
ECM detects the air flow by means of this current change.


DTC Logic


DTC DETECTION LOGIC

NOTE:
If DTC P0101 or P010B is displayed with other DTC, first perform the trouble diagnosis for other DTC.






DTC CONFIRMATION PROCEDURE


1. 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 2.

2. PERFORM DTC CONFIRMATION PROCEDURE

1.Start engine and warm it up to normal operating temperature.
2.Drive the vehicle for at least 5 seconds under the following conditions:

CAUTION:
Always drive vehicle at a safe speed.





NOTE:
- The gear must be fixed while driving the vehicle.
- Keep the accelerator pedal as steady as possible during cruising.
3.Check 1st trip DTC.
Is 1st trip DTC detected?
YES- Proceed to .
NO- INSPECTION END


Diagnosis Procedure


1. CHECK INTAKE SYSTEM

Check the following items to see the installation condition and the connection condition of the joint.
- Air duct
- Vacuum hoses
- Intake air passage between air duct and intake manifold
Is the inspection result normal?
YES- GO TO 2.
NO- Reconnect and replace error-detected parts.

2. CHECK GROUND CONNECTION

1.Turn ignition switch OFF.
2.Check ground connection M95. Refer to Ground Inspection in Circuit Inspection.
Is the inspection result normal?
YES- GO TO 3.
NO- Repair or replace ground connection.

3. CHECK MASS AIR FLOW (MAF) SENSOR POWER SUPPLY CIRCUIT

1.Disconnect MAF sensor harness connector.
2.Turn ignition switch ON.
3.Check the voltage between MAF sensor harness connector and ground.





Is the inspection result normal?
YES- GO TO 5.
NO- GO TO 4.

4. DETECT MALFUNCTIONING PART

Check the following.
- Harness connectors E106, M6
- Harness connectors M116, F103
- Harness for open or short between mass air flow sensor and ECM
- Harness for open or short between mass air flow sensor and IPDM E/R
- Repair open circuit or short to ground or short to power in harness or connectors.

5. CHECK MAF SENSOR GROUND CIRCUIT FOR OPEN AND SHORT

1.Turn ignition switch OFF.
2.Disconnect ECM harness connector.
3.Check the continuity between MAF sensor harness connector and ECM harness connector.





4.Also check harness for short to ground and short to power.
Is the inspection result normal?
YES- GO TO 6.
NO- Repair open circuit or short to ground or short to power in harness or connectors.

6. CHECK MAF SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT

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





2.Also check harness for short to ground and short to power.
Is the inspection result normal?
YES- GO TO 7.
NO- Repair open circuit or short to ground or short to power in harness or connectors.

7. CHECK INTAKE AIR TEMPERATURE SENSOR

Check intake air temperature sensor (bank 1). P0111.
Is the inspection result normal?
YES- GO TO 8.
NO- Replace MAF sensor (bank 1) (with intake air temperature sensor).

8. CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR

Check EVAP control system pressure sensor. P0451.
Is the inspection result normal?
YES- GO TO 9.
NO- Replace EVAP control system pressure sensor.

9. CHECK MAF SENSOR

Check MAF sensor. .
Is the inspection result normal?
YES- GO TO 10.
NO- Replace malfunctioning mass air flow sensor.

10. CHECK INTERMITTENT INCIDENT

Check intermittent incident. Intermittent Incident.
- INSPECTION END


Component Inspection


1. CHECK MASS AIR FLOW 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 "MAS A/F SE-B1" and "MAS A/F SE-B2", and check the indication.





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 voltage between ECM harness connector terminals under the following conditions.





Is the inspection result normal?
YES- GO TO 4.
NO- GO TO 2.

2. CHECK FOR THE CAUSE OF UNEVEN AIR FLOW THROUGH MASS AIR FLOW SENSOR

1.Turn ignition switch OFF.
2.Check for the cause of uneven air flow through mass air flow 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?
YES- GO TO 4.
NO- GO TO 3.

3. CHECK MASS AIR FLOW 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 "MAS A/F SE-B1" and "MAS A/F SE-B2", and check the indication.





Without CONSULT
1.Repair or replace malfunctioning part.
2.Start engine and warm it up to normal operating temperature.
3.Check the voltage between ECM harness connector terminals under the following conditions.





Is the inspection result normal?
YES- INSPECTION END
NO- GO TO 4.

4. CHECK MASS AIR FLOW SENSOR-III

With CONSULT
1.Turn ignition switch OFF.
2.Disconnect mass air flow 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 "MAS A/F SE-B1" and "MAS A/F SE-B2", and check the indication.





Without CONSULT
1.Turn ignition switch OFF.
2.Disconnect mass air flow sensor harness connector and reconnect it again.
3.Start engine and warm it up to normal operating temperature.
4.Check the voltage between ECM harness connector terminals under the following conditions.





Is the inspection result normal?
YES- INSPECTION END
NO- Clean or replace malfunctioning mass air flow sensor.