P0101
P0101 MAF SENSOR
Description
The mass air flow (MAF) 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 greater air flow, 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 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 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 P0101.
NO - INSPECTION END
Diagnosis Procedure
Regarding Wiring Diagram information, [1][2]Electrical Diagrams.
1.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?
YES - GO TO 2.
NO - Reconnect the parts.
2.CHECK GROUND CONNECTION
1. Turn ignition switch OFF.
2. Check ground connection E9. 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 mass air flow sensor harness connector.
2. Turn ignition switch ON.
3. Check the voltage between mass air flow 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 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, short to ground or short to power in harness or connectors.
5.CHECK MASS AIR FLOW SENSOR GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check the continuity between mass air flow 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, short to ground or short to power in harness or connectors.
6.CHECK MASS AIR FLOW SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Check the continuity between mass air flow 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, short to ground or short to power in harness or connectors.
7.CHECK INTAKE AIR TEMPERATURE (IAT) SENSOR
P0101.
Is the inspection result normal?
YES - GO TO 8.
NO - Replace mass air flow sensor (with intake air temperature sensor). Service and Repair.
8.CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR
P0451.
Is the inspection result normal?
YES - GO TO 9.
NO - Replace EVAP control system pressure sensor. Service and Repair.
9.CHECK MASS AIR FLOW SENSOR
P0101.
Is the inspection result normal?
YES - GO TO 10.
NO - Replace mass air flow sensor. Service and Repair.
10.CHECK INTERMITTENT INCIDENT
Intermittent Incident.
- INSPECTION END
Component Inspection
1.CHECK MASS AIR FLOW (MAF) SENSOR-I
With CONSULT-III
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-III and select "DATA MONITOR" mode.
5. Select "MAS A/F SE-B1" and check indication under the following conditions.
Without CONSULT-III
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 - INSPECTION END
NO - GO TO 2.
2.CHECK FOR THE CAUSE OF UNEVEN AIR FLOW VIA THE MASS AIR FLOW SENSOR
Check for the cause of uneven air flow via the 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-III
1. Repair or replace malfunctioning part.
2. Start engine and warm it up to normal operating temperature.
3. Connect CONSULT-III and select "DATA MONITOR" mode.
4. Select "MAS A/F SE-B1" and check indication under the following conditions.
Without CONSULT-III
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-III
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-III and select "DATA MONITOR" mode.
5. Select "MAS A/F SE-B1" and check indication under the following conditions.
Without CONSULT-III
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 mass air flow sensor. Service and Repair.