Dtc P0102 Mass Or Volume Air Flow Circuit Low Input

Engine Hybrid System. Land Cruiser. Urj200, 202 Grj200 Vdj200
1Gr-Fe Engine Control. Land Cruiser. Urj200, 202 Grj200 Vdj200

DESCRIPTION

MONITOR DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

READ OUTPUT DTC

INSPECT MASS AIR FLOW METER (POWER SOURCE VOLTAGE)

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

INSPECT MASS AIR FLOW METER

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

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

The mass air flow 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 mass air flow 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 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 either of these DTCs is 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. The ECM continues operating in fail-safe mode until a pass condition is detected.

Land Cruiser. Urj200, 202 Grj200 Vdj200.1Gr-Fe Engine Control.Sfi System. Dtc P0102 Mass Or Volume Air Flow Circuit Low Input


DTC No.
DTC Detection Condition
Trouble Area
P0102
Mass air flow meter voltage is below 0.2 V for 3 seconds
(1 trip detection logic)
  1. Open or short in mass air flow meter circuit
  2. Mass air flow meter
  3. ECM
P0103
Mass air flow meter voltage is higher than 4.9 V for 3 seconds
(1 trip detection logic)
  1. Open or short in mass air flow meter circuit
  2. Mass air flow meter
  3. ECM

HINT:
When either of these DTCs is stored, check the airflow rate by entering the following menus: Powertrain / Engine and ECT / Data List / All Data / MAF.

Mass Airflow Rate (gm/s)
Malfunction
Approximately 0.0
  1. Open in mass air flow meter power source circuit
  2. Open or short in VG circuit
160.0 or more
  1. Open in E2G circuit

MONITOR DESCRIPTION

If there is a defect in the mass air flow 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 mass air flow 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


Land Cruiser. Urj200, 202 Grj200 Vdj200.1Gr-Fe Engine Control.Sfi System. Dtc P0102 Mass Or Volume Air Flow Circuit Low Input


INSPECTION PROCEDURE

NOTICE:
Inspect the fuses for circuits related to this system before performing the following inspection procedure.
HINT:
Read freeze frame data using the GTS. 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 OUTPUT DTC

  1. Connect the GTS to the DLC3.

  1. Turn the ignition switch to ON.

  1. Turn the GTS on.

  1. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.

  1. Read the DTCs.

    Result
    Result
    		Proceed to
    DTC P0102 is output
    		A
    DTC P0103 is output
    		B


B
Go to step 6
A


2.INSPECT MASS AIR FLOW METER (POWER SOURCE VOLTAGE)
Land Cruiser. Urj200, 202 Grj200 Vdj200.1Gr-Fe Engine Control.Sfi System. Dtc P0102 Mass Or Volume Air Flow Circuit Low Input

  1. Disconnect the mass air flow meter connector.

  1. Turn the ignition switch to ON.

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

    Standard Voltage:
    Tester Connection
    		Switch Condition
    		Specified Condition
    C50-3 (+B) - Body ground
    		Ignition switch ON
    		11 to 14 V
    Text in Illustration
    *a
    		Front view of wire harness connector
    (to Mass Air Flow Meter)


NG
Go to step 5
OK


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

  1. Disconnect the mass air flow meter connector.

  1. Disconnect the ECM connector.

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

    Standard Resistance:
    for LHD
    Tester Connection
    		Condition
    		Specified Condition
    C50-5 (VG) - C45-74 (VG)
    		Always
    		Below 1 Ω
    C50-4 (E2G) - C45-75 (E2G)
    		Always
    		Below 1 Ω
    C50-5 (VG) or C45-74 (VG) - Body ground
    		Always
    		10 kΩ or higher
    for RHD
    Tester Connection
    		Condition
    		Specified Condition
    C50-5 (VG) - C46-74 (VG)
    		Always
    		Below 1 Ω
    C50-4 (E2G) - C46-75 (E2G)
    		Always
    		Below 1 Ω
    C50-5 (VG) or C46-74 (VG) - Body ground
    		Always
    		10 kΩ or higher


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


4.INSPECT MASS AIR FLOW METER

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



NG
REPLACE MASS AIR FLOW METER (Click here)
OK

REPLACE ECM (Click here)

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

  1. Disconnect the mass air flow 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
    C50-3 (+B) - 1B-4
    		Always
    		Below 1 Ω
    C50-3 (+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 (SENSOR GROUND)

  1. Disconnect the mass air flow meter connector.

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    C50-4 (E2G) - Body ground
    		Always
    		Below 1 Ω


NG
Go to step 7
OK

REPLACE MASS AIR FLOW METER (Click here)

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

  1. Disconnect the mass air flow meter connector.

  1. Disconnect the ECM connector.

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

    Standard Resistance:
    for LHD
    Tester Connection
    		Condition
    		Specified Condition
    C50-5 (VG) - C45-74 (VG)
    		Always
    		Below 1 Ω
    C50-4 (E2G) - C45-75 (E2G)
    		Always
    		Below 1 Ω
    C50-5 (VG) or C45-74 (VG) - Body ground
    		Always
    		10 kΩ or higher
    for RHD
    Tester Connection
    		Condition
    		Specified Condition
    C50-5 (VG) - C46-74 (VG)
    		Always
    		Below 1 Ω
    C50-4 (E2G) - C46-75 (E2G)
    		Always
    		Below 1 Ω
    C50-5 (VG) or C46-74 (VG) - Body ground
    		Always
    		10 kΩ or higher


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

REPLACE ECM (Click here)