Dtc P0102 Mass Or Volume Air Flow Circuit Low Input

Engine Hybrid System. Land Cruiser. Urj200, 202 Grj200 Vdj200
3Ur-Fe Engine Control. Land Cruiser. Urj200, 202 Grj200 Vdj200

DESCRIPTION

MONITOR DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

READ VALUE USING INTELLIGENT TESTER (MASS AIR FLOW RATE)

INSPECT MASS AIR FLOW METER (POWER SOURCE VOLTAGE)

INSPECT MASS AIR FLOW METER

CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM)

CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - INTEGRATION RELAY)

CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM)

CHECK HARNESS AND CONNECTOR (SENSOR GROUND)

DTC P0102 Mass or Volume Air Flow Circuit Low Input

DTC P0103 Mass or Volume Air Flow Circuit High Input


DESCRIPTION

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 these components in the MAF meter. 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 cold film element 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.

Land Cruiser. Urj200, 202 Grj200 Vdj200.3Ur-Fe Engine Control.Sfi System. Dtc P0102 Mass Or Volume Air Flow Circuit Low Input


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).
  1. Open or short in Mass Air Flow (MAF) meter circuit
  2. MAF meter
  3. ECM
P0103
The MAF meter voltage is higher than 4.9 V for 3 seconds (1 trip detection logic).
  1. Open or short in MAF meter circuit
  2. MAF meter
  3. ECM

HINT:
When any of these DTCs is output, check the air-flow rate by entering the following menus: Powertrain / Engine and ECT / Data List / All Data / MAF.

Mass Air Flow Rate (gm/s)
Malfunction
Approximately 0.0
  1. Open in Mass Air Flow (MAF) meter power source circuit
  2. Open or short in VG circuit
160.0 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 DTC(s).
Example:
When the sensor output voltage remains at below 0.2 V, or higher than 4.9 V for more than 3 seconds, the ECM stores DTC(s).
If the malfunction is not repaired successfully, a DTC is stored 3 seconds after the engine is next started.

WIRING DIAGRAM


Land Cruiser. Urj200, 202 Grj200 Vdj200.3Ur-Fe Engine Control.Sfi System. Dtc P0102 Mass Or Volume Air Flow Circuit Low Input


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 AIR FLOW RATE)

  1. Connect the intelligent tester to the DLC3.

  1. Start the engine.

  1. Turn the tester on.

  1. Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / MAF.

  1. Read the values displayed on the tester.

    Result
    Mass Air Flow Rate (gm/s)
    		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.


B
Go to step 6

C
CHECK FOR INTERMITTENT PROBLEMS (Click here)
A


2.INSPECT MASS AIR FLOW METER (POWER SOURCE VOLTAGE)
Land Cruiser. Urj200, 202 Grj200 Vdj200.3Ur-Fe Engine Control.Sfi System. Dtc P0102 Mass Or Volume Air Flow Circuit Low Input

  1. Disconnect the C50 Mass Air Flow (MAF) meter connector.

  1. Measure the voltage according to the value(s) in the table below.

    Standard Voltage:
    Tester Connection
    		Switch Condition
    		Specified Condition
    C50-1 (+B) - Body ground
    		Engine switch on (IG)
    		11 to 14 V


NG
Go to step 5
OK


3.INSPECT MASS AIR FLOW METER

  1. Inspect the mass air flow meter assembly (Click here)



NG
REPLACE MASS AIR FLOW METER (Click here)
OK


4.CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM)

  1. Disconnect the C50 MAF meter connector.

  1. Disconnect the C45 ECM connector.

  1. Measure the resistance according to the value(s) in the table below.

    Standard Resistance:

    Tester Connection
    		Condition
    		Specified Condition
    C50-3 (VG) - C45-74 (VG)
    		Always
    		Below 1 Ω
    C50-2 (E2G) - C45-75 (E2G)
    		Always
    		Below 1 Ω
    C50-3 (VG) or C45-74 (VG) - Body ground
    		Always
    		10 kΩ or higher


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

REPLACE ECM (Click here)

5.CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - INTEGRATION RELAY)

  1. Check the EFI NO. 2 fuse.

    1. Remove the EFI NO. 2 fuse from the engine room relay block.

    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance:

      Tester Connection
      		Condition
      		Specified Condition
      EFI NO. 2 fuse
      		Always
      		Below 1 Ω

    3. Reinstall the EFI NO. 2 fuse.

  1. Disconnect the C50 MAF meter connector.

  1. Remove the integration relay from the engine room relay block.

  1. Measure the resistance according to the value(s) in the table below.

    Standard Resistance:

    Tester Connection
    		Condition
    		Specified Condition
    C50-1 (+B) - 1B-4
    		Always
    		Below 1 Ω
    C50-1 (+B) or 1B-4 - Body ground
    		Always
    		10 kΩ or higher


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

CHECK ECM POWER SOURCE CIRCUIT (Click here)

6.CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM)

  1. Disconnect the C50 MAF meter connector.

  1. Disconnect the C45 ECM connector.

  1. Measure the resistance according to the value(s) in the table below.

    Standard Resistance:

    Tester Connection
    		Condition
    		Specified Condition
    C50-3 (VG) - C45-74 (VG)
    		Always
    		Below 1 Ω
    C50-2 (E2G) - C45-75 (E2G)
    		Always
    		Below 1 Ω
    C50-3 (VG) or C45-74 (VG) - Body ground
    		Always
    		10 kΩ or higher


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


7.CHECK HARNESS AND CONNECTOR (SENSOR GROUND)
Land Cruiser. Urj200, 202 Grj200 Vdj200.3Ur-Fe Engine Control.Sfi System. Dtc P0102 Mass Or Volume Air Flow Circuit Low Input

  1. Disconnect the C50 MAF meter connector.

  1. Measure the resistance according to the value(s) in the table below.

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    C50-2 (E2G) - Body ground
    		Always
    		Below 1 Ω


NG
REPLACE ECM (Click here)
OK

REPLACE MASS AIR FLOW METER (Click here)