Dtc P0102 Mass Or Volume Air Flow Circuit Low Input

Engine. Toyota Rav4. Aca30, 33, 38 Gsa33 Zsa30, 35
3Zr-Fae Engine Control System. Toyota Rav4. Aca30, 33, 38 Gsa33 Zsa30, 35

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

CHECK DTC OUTPUT

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 MAIN))

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 these components in the mass air flow meter. The voltage level is proportional to the air flow 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 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.

Toyota Rav4. Aca30, 33, 38 Gsa33 Zsa30, 35.3Zr-Fae Engine Control System.Sfi System. Dtc P0102 Mass Or Volume Air Flow Circuit Low Input


DTC No.
DTC Detection Condition
Trouble Area
P0102
The 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
The 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 are output, check the air-flow rate using the intelligent tester. Enter the following menus: Powertrain / Engine and ECT / Data List / MAF.

Mass Air Flow Rate (g/sec.)
Malfunction
Approximately 0.26
  1. Open in mass air flow meter power source circuit
  2. Open or short in VG circuit
271.0 or more
  1. Open in E2G circuit

WIRING DIAGRAM


Toyota Rav4. Aca30, 33, 38 Gsa33 Zsa30, 35.3Zr-Fae Engine Control System.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 intelligent tester. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. 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.CHECK DTC OUTPUT

  1. Connect the intelligent tester to the DLC3.

  1. Turn the ignition switch to ON.

  1. Turn the tester on.

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

  1. Read the DTC.

    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)


    Toyota Rav4. Aca30, 33, 38 Gsa33 Zsa30, 35.3Zr-Fae Engine Control System.Sfi System. Dtc P0102 Mass Or Volume Air Flow Circuit Low Input

  1. Disconnect the mass air flow meter connector.

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

    Standard Voltage:
    Tester Connection
    		Switch Condition
    		Specified Condition
    B1-3 (+B) - Body ground
    		Ignition switch ON
    		11 to 14 V
    Text in Illustration
    *1
    		Front view of wire harness connector
    (to Mass Air Flow Meter)

  1. Reconnect the mass air flow meter connector.



NG
Go to step 5
OK


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


    Toyota Rav4. Aca30, 33, 38 Gsa33 Zsa30, 35.3Zr-Fae Engine Control System.Sfi System. Dtc P0102 Mass Or Volume Air Flow Circuit Low Input

  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 (Check for Open):
    Tester Connection
    		Condition
    		Specified Condition
    B1-5 (VG) - B32-69 (VG)
    		Always
    		Below 1 Ω
    B1-4 (E2G) - B32-92 (E2G)
    		Always
    		Below 1 Ω
    Standard Resistance (Check for Short):
    Tester Connection
    		Condition
    		Specified Condition
    B1-5 (VG) or B32-69 (VG) - Body ground
    		Always
    		10 kΩ or higher
    Text in Illustration
    *1
    		Front view of wire harness connector
    (to Mass Air Flow Meter)
    *2
    		Front view of wire harness connector
    (to ECM)

  1. Reconnect the mass air flow meter connector.

  1. Reconnect the ECM connector.



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR (MASS AIR FLOW METER - ECM)
OK


4.INSPECT MASS AIR FLOW METER

  1. Inspect the mass air flow meter (RAV4_ACA30 RM000000VA5015X.html).



NG
REPLACE MASS AIR FLOW METER (RAV4_ACA30 RM000002WQT00SX.html)
OK

REPLACE ECM (RAV4_ACA30 RM0000017UO01KX.html)

5.CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - INTEGRATION RELAY (EFI MAIN))
Toyota Rav4. Aca30, 33, 38 Gsa33 Zsa30, 35.3Zr-Fae Engine Control System.Sfi System. Dtc P0102 Mass Or Volume Air Flow Circuit Low Input

  1. Disconnect the mass air flow meter connector.

  1. Remove the integration relay (EFI MAIN relay) from the engine room No. 1 relay block.

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

    Standard Resistance (Check for Open):
    Tester Connection
    		Condition
    		Specified Condition
    B1-3 (+B) - 1A-4
    		Always
    		Below 1 Ω
    Standard Resistance (Check for Short):
    Tester Connection
    		Condition
    		Specified Condition
    B1-3 (+B) or 1A-4 - Body ground
    		Always
    		10 kΩ or higher
    Text in Illustration
    *1
    		Front view of wire harness connector
    (to Mass Air Flow Meter)
    *2
    		Front view of wire harness connector
    (to Integration Relay)
    *3
    		Engine Room No. 1 Relay Block

  1. Reconnect the mass air flow meter connector.

  1. Reinstall the integration relay.



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR (MASS AIR FLOW METER - INTEGRATION RELAY (EFI MAIN))
OK

GO TO ECM POWER SOURCE CIRCUIT (RAV4_ACA30 RM00000276902PX.html)

6.CHECK HARNESS AND CONNECTOR (SENSOR GROUND)


    Toyota Rav4. Aca30, 33, 38 Gsa33 Zsa30, 35.3Zr-Fae Engine Control System.Sfi System. Dtc P0102 Mass Or Volume Air Flow Circuit Low Input

  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
    B1-4 (E2G) - Body ground
    		Always
    		Below 1 Ω
    Text in Illustration
    *1
    		Front view of wire harness connector
    (to Mass Air Flow Meter)

  1. Reconnect the mass air flow meter connector.



NG
Go to step 7
OK

REPLACE MASS AIR FLOW METER (RAV4_ACA30 RM000002WQT00SX.html)

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


    Toyota Rav4. Aca30, 33, 38 Gsa33 Zsa30, 35.3Zr-Fae Engine Control System.Sfi System. Dtc P0102 Mass Or Volume Air Flow Circuit Low Input

  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 (Check for Open):
    Tester Connection
    		Condition
    		Specified Condition
    B1-4 (E2G) - B32-92 (E2G)
    		Always
    		Below 1 Ω
    Standard Resistance (Check for Short):
    Tester Connection
    		Condition
    		Specified Condition
    B1-4 (E2G) or B32-92 (E2G) - Body ground
    		Always
    		10 kΩ or higher
    Text in Illustration
    *1
    		Front view of wire harness connector
    (to Mass Air Flow Meter)
    *2
    		Front view of wire harness connector
    (to ECM)

  1. Reconnect the mass air flow meter connector.

  1. Reconnect the ECM connector.



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR (MASS AIR FLOW METER - ECM)
OK

REPLACE ECM (RAV4_ACA30 RM0000017UO01KX.html)