For USA (Federal) And Canada
P0101 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 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
DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
If DTC Confirmation Procedure has been previously conducted, always perform the following 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.
If engine will not start or stops soon, wait at least 10 seconds with engine stopped (Ignition switch ON) instead of running engine at idle speed.
- GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE FOR MALFUNCTION A
1. Start engine and warm it up to normal operating temperature.
2. Run engine for at least 10 seconds at idle speed.
3. Check 1st trip DTC.
Is 1st trip DTC detected?
YES - Go to For USA (Federal) And Canada.
NO-1 - With CONSULT-III: GO TO 3.
NO-2 - Without CONSULT-III: GO TO 5.
3.CHECK MASS AIR FLOW SENSOR FUNCTION
1. Turn ignition switch ON.
2. Start engine and warm it up to normal operating temperature.
If engine cannot be started, go to For USA (Federal) And Canada.
3. Select "DATA MONITOR" mode with CONSULT-III.
4. Check the voltage of "MAS A/F SE-B1" with "DATA MONITOR".
5. Increases engine speed to approximately 4,000 rpm.
6. Monitor the linear voltage rise in response to engine speed increases.
Is the inspection result normal?
YES - GO TO 4.
NO - Go to For USA (Federal) And Canada.
4.PERFORM DTC CONFIRMATION PROCEDURE FOR MALFUNCTION B
1. Maintain the following conditions for at least 10 consecutive seconds.
CAUTION:
Always drive vehicle at a safe speed.
2. Check 1st trip DTC.
Is 1st trip DTC detected?
YES - Go to For USA (Federal) And Canada.
NO - INSPECTION END
5.PERFORM COMPONENT FUNCTION CHECK FOR MALFUNCTION B
Perform component function check. For USA (Federal) And Canada.
NOTE:
Use component function check to check the overall function of the mass air flow sensor circuit. During this check, a 1st trip DTC might not be confirmed.
Is the inspection result normal?
YES - INSPECTION END
NO - Go to For USA (Federal) And Canada.
Component Function Check
1.PERFORM COMPONENT FUNCTION CHECK FOR MALFUNCTION B
With GST
1. Start engine and warm it up to normal operating temperature.
2. Select Service $01 with GST.
3. Check the mass air flow sensor signal with Service $01.
4. Check for linear mass air flow sensor signal value rise in response to increases to approximately 4,000 rpm in engine speed.
Is the inspection result normal?
YES - INSPECTION END
NO - Go to For USA (Federal) And Canada.
Diagnosis Procedure
1.INSPECTION START
Confirm the detected malfunction (A or B). For USA (Federal) And Canada.
Which malfunction is detected?
A - GO TO 3.
B - GO TO 2.
2.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 3.
NO - Reconnect the parts.
3.CHECK GROUND CONNECTION
1. Turn ignition switch OFF.
2. Check ground connection E21. Refer to Ground Inspection in Circuit Inspection.
Is the inspection result normal?
YES - GO TO 4.
NO - Repair or replace ground connection.
4.CHECK MAF SENSOR POWER SUPPLY CIRCUIT
1. Disconnect mass air flow (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 6.
NO - GO TO 5.
5.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 or short to ground or short to power in harness or connectors.
6.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 8.
NO - GO TO 7.
7.DETECT MALFUNCTIONING PART
Check the following.
- Harness connectors E6, F123
- Harness for open or short between mass air flow sensor and ECM
- Repair open circuit or short to ground or short to power in harness or connectors.
8.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 10.
NO - GO TO 9.
9.DETECT MALFUNCTIONING PART
Check the following.
- Harness connectors E6, F123
- Harness for open or short between mass air flow sensor and ECM
- Repair open circuit or short to ground or short to power in harness or connectors.
10.CHECK INTAKE AIR TEMPERATURE SENSOR
For USA (Federal) And Canada.
Is the inspection result normal?
YES - GO TO 11.
NO - Replace mass air flow sensor (with intake air temperature sensor).
11.CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR
For USA (Federal) And Canada.
Is the inspection result normal?
YES - GO TO 12.
NO - Replace EVAP control system pressure sensor.
12.CHECK MASS AIR FLOW SENSOR
For USA (Federal) And Canada.
Is the inspection result normal?
YES - GO TO 13.
NO - Replace mass air flow sensor.
13.CHECK INTERMITTENT INCIDENT
Intermittent Incident.
- INSPECTION END
Component Inspection
1.CHECK MASS AIR FLOW 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.
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 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-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.
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.
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.