READ VALUE USING INTELLIGENT TESTER (MASS AIRFLOW RATE)
INSPECT MASS AIR FLOW METER (POWER SOURCE VOLTAGE)
CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM)
CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - EFI NO. 2 FUSE)
CHECK HARNESS AND CONNECTOR (SENSOR GROUND)
CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM)
DTC P0102 Mass or Volume Air Flow Circuit Low Input
DTC P0103 Mass or Volume Air Flow Circuit High Input
Description DTC P0102 P0103
The Mass Air Flow (MAF) meter is a sensor that measures the amount of air flowing through the throttle valve.
The ECM uses this information to determine the fuel injection time and to provide the appropriate air fuel ratio.
Inside the MAF meter, there is a heated platinum wire which is exposed to the flow of intake air.
By applying a specific electrical current to the wire, the ECM heats it to a given temperature. The flow of incoming air cools both the wire and an internal thermistor, affecting their resistance. To maintain a constant current value, the ECM varies the voltage applied to the wire and internal thermistor. The voltage level is proportional to the airflow through the sensor, and the ECM uses it to calculate the intake air volume.
The circuit is constructed so that the platinum hot wire and the temperature sensor create a bridge circuit, and the power transistor is controlled so that the potentials of A and B remain equal to maintain the predetermined temperature.
HINT:
When any of these DTCs are stored, the ECM enters fail-safe mode. During fail-safe mode, the ignition timing is calculated by the ECM, according to the engine speed and throttle valve position. Fail-safe mode continues until a pass condition is detected.
DTC Code | DTC Detection Condition | Trouble Area |
P0102 | The Mass Air Flow (MAF) meter voltage is below 0.2 V for 3 seconds (1 trip detection logic). |
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P0103 | The MAF meter voltage is higher than 4.9 V for 3 seconds (1 trip detection logic). |
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HINT:
When any of these DTCs are output, check the airflow rate by entering the following menus: Powertrain / Engine and ECT / Data List / All Data / MAF.
Mass Airflow Rate (g/sec.) | Malfunction |
Approximately 0.0 |
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271.0 or more | Open in E2G circuit |
Monitor description
If there is a defect in the MAF meter or an open or short circuit, the voltage level deviates from the normal operating range. The ECM interprets this deviation as a malfunction in the MAF meter and stores a DTC.
Example:
When the sensor output voltage remains below 0.2 V, or higher than 4.9 V, for more than 3 seconds, the ECM stores a DTC.
If the malfunction is not repaired successfully, a DTC is stored 3 seconds after the engine is next started.
Wiring diagram
Inspection procedure
HINT:
Read freeze frame data using the intelligent tester. Freeze frame data records the engine condition when malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air fuel ratio was lean or rich, and other data from the time the malfunction occurred.
1.READ VALUE USING INTELLIGENT TESTER (MASS AIRFLOW RATE)
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Connect the intelligent tester to the DLC3.
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Start the engine.
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Turn the tester on.
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Enter the following menus: Powertrain / Engine and ECT / Data List / MAF.
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Read the values displayed on the tester.
Result Mass Airflow Rate (g/sec.) Proceed to 0.0 A 271.0 or more B Between 1.0 and 270.0* C HINT:
*: The value must change when the throttle valve is open or closed with the engine running.
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A | |
2.INSPECT MASS AIR FLOW METER (POWER SOURCE VOLTAGE)
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Disconnect the Mass Air Flow (MAF) meter connector.
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Measure the voltage according to the value(s) in the table below.
Standard Voltage:
Tester Connection Switch Condition Specified Condition C2-1 (+B) - Body ground Ignition switch ON 11 to 14 V
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OK | |
3.INSPECT MASS AIR FLOW METER
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Inspect the mass air flow meter.
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OK | |
4.CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM)
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Disconnect the ECM connector.
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Measure the resistance according to the value(s) in the table below.
Standard Resistance (Check for Open):
for LHD Tester Connection Condition Specified Condition C2-3 (VG) - C45-72 (VG) Always Below 1 ? C2-2 (E2G) - C45-73 (E2G) Always Below 1 ? for RHD Tester Connection Condition Specified Condition C2-3 (VG) - C46-72 (VG) Always Below 1 ? C2-2 (E2G) - C46-73 (E2G) Always Below 1 ? Standard Resistance (Check for Short):
for LHD Tester Connection Condition Specified Condition C2-3 (VG) or C45-72 (VG) - Body ground Always 10 k? or higher C2-2 (E2G) or C45-73 (E2G) - Body ground Always 10 k? or higher for RHD Tester Connection Condition Specified Condition C2-3 (VG) or C46-72 (VG) - Body ground Always 10 k? or higher C2-2 (E2G) or C46-73 (E2G) - Body ground Always 10 k? or higher
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OK | |
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5.CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - EFI NO. 2 FUSE)
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Remove the EFI NO. 2 fuse from the engine room relay block.
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Measure the resistance according to the value(s) in the table below.
Standard Resistance (Check for Open):
Tester Connection Condition Specified Condition C2-1 (+B) - EFI NO. 2 fuse (2) Always Below 1 ? Standard Resistance (Check for Short):
Tester Connection Condition Specified Condition C2-1 (+B) or EFI NO. 2 fuse (2) - Body ground Always 10 k? or higher
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OK | |
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6.CHECK HARNESS AND CONNECTOR (SENSOR GROUND)
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Disconnect the MAF meter connector.
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Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Tester Connection Condition Specified Condition C2-2 (E2G) - Body ground Always Below 1 ?
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OK | |
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7.CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM)
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Disconnect the ECM connector.
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Measure the resistance according to the value(s) in the table below.
Standard Resistance (Check for Open):
for LHD Tester Connection Condition Specified Condition C2-2 (E2G) - C45-73 (E2G) Always Below 1 ? for RHD Tester Connection Condition Specified Condition C2-2 (E2G) - C46-73 (E2G) Always Below 1 ? Standard Resistance (Check for Short):
for LHD Tester Connection Condition Specified Condition C2-2 (E2G) or C45-73 (E2G) - Body ground Always 10 k? or higher for RHD Tester Connection Condition Specified Condition C2-2 (E2G) or C46-73 (E2G) - Body ground Always 10 k? or higher
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OK | |
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