DTC    P0100    Mass or Volume Air Flow Circuit

DTC    P0102    Mass or Volume Air Flow Circuit Low Input

DTC    P0103    Mass or Volume Air Flow Circuit High Input

for Preparation Click here


DESCRIPTION

The Mass Air Flow (MAF) meter is a sensor that measures the amount of air flowing through the valve.
The ECM (Included in HV Control ECU) uses this information to determine the fuel injection time and to prove 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 temperature sensor provide 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 set, the ECM enters fail-safe mode. During fail-safe mode, the ignition timing is calculated by the ECM, according to the engine RPM and throttle valve position. Fail-safe mode continues until a pass condition is detected.


A094565E03


DTC No.
DTC Detection Condition
Trouble Area
P0100
Open or short in Mass Air Flow (MAF) meter circuit for 3 seconds
  1. Open or short in MAF meter circuit
  2. MAF meter
  3. HV Control ECU
P0102
Open in Mass Air Flow (MAF) meter circuit for 3 seconds
  1. Open in MAF meter circuit
  2. Short in MAF meter circuit
  3. MAF meter
  4. HV Control ECU
P0103
Short in Mass Air Flow (MAF) meter circuit for 3 seconds
  1. Short in MAF meter circuit (+B circuit)
  2. MAF meter
  3. HV Control ECU

HINT:
When any of these DTCs are set, check the air-flow rate by entering the following menus on the intelligent tester: Powertrain / Engine / Data List / MAF.

Mass Air Flow Rate (gm/s)
Malfunctions
Approximately 0.0
  1. Open in Mass Air Flow (MAF) meter power source circuit
  1. Open or short in VG circuit
271.0 or more
  1. Open in EVG circuit


WIRING DIAGRAM


A110943E04


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.READ VALUE USING INTELLIGENT TESTER (MASS AIR FLOW RATE)

  1. Connect the intelligent tester to the DLC3.

  1. Put the engine in inspection mode (Click here).

  1. Start the engine.

  1. Turn the tester ON.

  1. Enter the following menus: Powertrain / Engine / Data List / 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 (*1)
    		C

    *1: The value must be changed when the throttle valve is open or closed.



B
Go to step 6

C
CHECK FOR INTERMITTENT PROBLEMS
A


2.INSPECT MASS AIR FLOW METER (POWER SOURCE VOLTAGE)


    A054396E37

  1. Disconnect the A3 Mass Air Flow (MAF) meter connector.

  1. Turn the ignition switch ON.

  1. Measure the voltage between the terminals of the wire harness side connector and body ground.

    Standard voltage:
    Tester Connection
    		Specified Condition
    +B (A3-1) - Body ground
    		9 to 14 V

  1. Reconnect the MAF meter connector.



NG
Go to step 5
OK


3.INSPECT HV CONTROL ECU (VG VOLTAGE)


    A103828E78

  1. Put the engine in inspection mode (Click here).

  1. Start the engine.

  1. Measure the voltage between the terminals VG and EVG of the H34 HV Control ECU connector.

    Standard voltage:
    Tester Connection
    		Condition
    		Specified Condition
    VG (H34-30) - EVG (H34-29)
    		Engine idling
    		0.5 to 3.0 V



OK
REPLACE HV CONTROL ECU
NG


4.CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - HV CONTROL ECU)


    A110900E03

  1. Disconnect the A3 MAF meter connector.

  1. Disconnect the H34 HV Control ECU connector.

  1. Measure the resistance between the terminals of the MAF meter connector and HV Control ECU.

    Standard resistance (Check for open):
    Tester Connection
    		Specified Condition
    VG (A3-3) - VG (H34-30)
    		Below 1 Ω
    E2G (A3-2) - EVG (H34-29)
    		Below 1 Ω

    Standard resistance (Check for short):
    Tester Connection
    		Specified Condition
    VG(A3-3) or VG (H34-30) - Body ground
    		10 kΩ or higher

  1. Reconnect the MAF meter connector.

  1. Reconnect the HV Control ECU connector.



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

REPLACE MASS AIR FLOW METER 

5.CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - IGCT NO.4 FUSE)


    A110901E02

  1. Inspect the IGCT No.4 fuse.

    1. Remove the IGCT No.4 fuse from the R/B No.3.

    2. Check the IGCT No.4 fuse resistance.

      Standard resistance:
      Below 1 Ω

    3. Reinstall the IGCT No.4 fuse.

  1. Disconnect the A3 MAF meter connector.

  1. Remove the integration relay from the R/B No.3.

  1. Measure the resistance between terminal of the MAF meter and IGCT No.4 fuse.

    Standard resistance (Check for open):
    Tester Connection
    		Specified Condition
    +B (A3-1) - IGCT No.4 fuse (2)
    		Below 1 Ω

    Standard resistance (Check for short):
    Tester Connection
    		Specified Condition
    +B (A3-1) or IGCT No.4 fuse (2) - Body ground
    		10 kΩ or higher

  1. Reconnect the MAF meter connector.

  1. Reinstall the integration relay.



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

CHECK ECM (INCLUDED IN HV CONTROL ECU) POWER SOURCE CIRCUIT 

6.INSPECT HV CONTROL ECU (SENSOR GROUND)


    A103828E79

  1. Measure the resistance between terminals of the EVG and body ground.

    Standard resistance:
    Tester Connection
    		Specified Condition
    EVG (H34-29) - Body ground
    		Below 1 Ω



NG
REPLACE HV CONTROL ECU
OK


7.CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - HV CONTROL ECU)


    A110900E03

  1. Disconnect the A3 MAF meter connector.

  1. Disconnect the H34 HV Control ECU connector.

  1. Measure the resistance between terminals of the MAF meter and HV Control ECU.

    Standard resistance (Check for open):
    Tester Connection
    		Specified Condition
    VG (A3-3) - VG (H34-30)
    		Below 1 Ω
    E2G (A3-2) - EVG (H34-29)
    		Below 1 Ω

    Standard resistance (Check for short):
    Tester Connection
    		Specified Condition
    VG (A3-3) or VG (H34-30) - Body ground
    		10 kΩ or higher

  1. Reconnect the MAF meter connector.

  1. Reconnect the HV Control ECU connector.



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

REPLACE MASS AIR FLOW METER