Dtc P0100 Mass Or Volume Air Flow Circuit

Engine. Camry. Acv40 Gsv40
2Az-Fe Engine Control System. Camry. Acv40 Gsv40

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 (VG VOLTAGE)

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

INSPECT ENGINE ROOM J/B (EFI RELAY, EFI MAIN FUSE)

CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ENGINE ROOM J/B)

CHECK HARNESS AND CONNECTOR (SENSOR GROUND)

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

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


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 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 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.

Camry. Acv40 Gsv40.2Az-Fe Engine Control System.Sfi System. Dtc P0100 Mass Or Volume Air Flow Circuit


DTC No.
DTC Detection Condition
Trouble Area
P0100
MAF meter voltage less than 0.2 V, or more than 4.9 V for 3 seconds
(1 trip detection logic)
  1. Open or short in MAF meter circuit
  1. MAF meter
  1. ECM
P0102
MAF meter voltage less than 0.2 V for 3 seconds
(1 trip detection logic)
  1. Open or short in MAF meter circuit
  1. MAF meter
  1. ECM
P0103
MAF meter voltage more than 4.9 V for 3 seconds
(1 trip detection logic)
  1. Open or short in MAF meter circuit
  1. MAF meter
  1. ECM

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

Mass Air Flow Rate (g/sec.)
Malfunction
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 E2G circuit

WIRING DIAGRAM


Camry. Acv40 Gsv40.2Az-Fe Engine Control System.Sfi System. Dtc P0100 Mass Or Volume Air Flow Circuit


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. Start the engine and turn the tester on.

  1. Select the following menu items: Powertrain / Engine and ECT / Data List / MAF.

  1. Read the values displayed on the tester.

    Result:
    Mass Air Flow Rate (g/sec.)
    		Proceed to
    0.0
    		A
    271.0 or more
    		B
    Between 1.0 and 270.0 (*1)
    		C
    *1: The value must change when the throttle valve is open or closed with the engine running.


B
Go to step 7

C
CHECK FOR INTERMITTENT PROBLEMS
A


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


    Camry. Acv40 Gsv40.2Az-Fe Engine Control System.Sfi System. Dtc P0100 Mass Or Volume Air Flow Circuit

  1. Disconnect the C2 Mass Air Flow (MAF) meter connector.

  1. Turn the ignition switch to the ON position.

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

    Standard voltage:
    Tester Connection
    		Specified Condition
    +B (C2-3) - Body ground
    		9 to 14 V

  1. Reconnect the MAF meter connector.



NG
Go to step 5
OK


3.INSPECT MASS AIR FLOW METER (VG VOLTAGE)


    Camry. Acv40 Gsv40.2Az-Fe Engine Control System.Sfi System. Dtc P0100 Mass Or Volume Air Flow Circuit

  1. Inspect output voltage.

    1. Disconnect the C2 MAF meter connector.

    2. Apply battery voltage across terminals +B and E2G.

    3. Connect the positive (+) tester probe to terminal VG, and the negative (-) tester probe to terminal E2G.

    4. Measure the voltage.

      Standard voltage:
      Tester Connection
      		Specified Condition
      VG (5) - E2G (4)
      		0.2 to 4.9 V

    5. Reconnect the MAF meter connector.



NG
REPLACE MASS AIR FLOW METER
OK


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


    Camry. Acv40 Gsv40.2Az-Fe Engine Control System.Sfi System. Dtc P0100 Mass Or Volume Air Flow Circuit

  1. Disconnect the C2 MAF meter connector.

  1. Disconnect the C24 ECM connector.

  1. Measure the resistance between the terminals of the wire harness side connectors.

    Standard resistance (Check for open):
    Tester Connection
    		Specified Condition
    VG (C2-5) - VG (C24-118)
    		Below 1 Ω
    E2G (C2-4) - E2G (C24-116)
    Standard resistance (Check for short):
    Tester Connection
    		Specified Condition
    VG (C2-5) or VG (C24-118) - Body ground
    		10 kΩ or higher

  1. Reconnect the MAF meter connector.

  1. Reconnect the ECM connector.



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

REPLACE ECM

5.INSPECT ENGINE ROOM J/B (EFI RELAY, EFI MAIN FUSE)


    Camry. Acv40 Gsv40.2Az-Fe Engine Control System.Sfi System. Dtc P0100 Mass Or Volume Air Flow Circuit

  1. Inspect the EFI MAIN fuse.

    1. Remove the EFI MAIN fuse from the engine room J/B.

    2. Measure the EFI MAIN fuse resistance.

      Standard resistance:
      Below 1 Ω

    3. Reinstall the EFI MAIN fuse.

  1. Inspect the EFI relay.

    1. Remove the engine room J/B from the engine room R/B.

    2. Measure the EFI relay resistance.

      Standard resistance:
      Tester Connection
      		Specified Condition
      1E-6 - 1E-12
      		10 kΩ or higher
      Below 1 Ω
      (Apply battery voltage between terminals 1E-9 and 1E-11)

    3. Reinstall the engine room J/B.



NG
REPLACE ENGINE ROOM J/B AND/OR EFI MAIN FUSE
OK


6.CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ENGINE ROOM J/B)


    Camry. Acv40 Gsv40.2Az-Fe Engine Control System.Sfi System. Dtc P0100 Mass Or Volume Air Flow Circuit

  1. Inspect the EFI No. 3 fuse.

    1. Remove the EFI No. 3 fuse from the engine room R/B.

    2. Measure the EFI No. 3 fuse resistance.

      Standard resistance:
      Below 1 Ω

    3. Reinstall the EFI No. 3 fuse.

  1. Disconnect the C2 MAF meter connector.

  1. Remove the engine room J/B from the engine room R/B.

  1. Disconnect the 1E engine room J/B connector.

  1. Measure the resistance between the terminals.

    Standard resistance (Check for open):
    Tester Connection
    		Specified Condition
    +B (C2-3) - Engine room J/B (1E-6)
    		Below 1 Ω
    Standard resistance (Check for short):
    Tester Connection
    		Specified Condition
    +B (C2-3) or Engine room J/B (1E-6) - Body ground
    		10 kΩ or higher

  1. Reconnect the MAF meter connector.

  1. Reconnect the engine room J/B connector.

  1. Reinstall the engine room J/B.



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

CHECK ECM POWER SOURCE CIRCUIT

7.CHECK HARNESS AND CONNECTOR (SENSOR GROUND)


    Camry. Acv40 Gsv40.2Az-Fe Engine Control System.Sfi System. Dtc P0100 Mass Or Volume Air Flow Circuit

  1. Disconnect the C2 MAF meter connector.

  1. Measure the resistance.

    Standard resistance:
    Tester Connection
    		Specified Condition
    E2G (C2-4) - Body ground
    		Below 1 Ω

  1. Reconnect the MAF meter connector.



OK
REPLACE MASS AIR FLOW METER
NG


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


    Camry. Acv40 Gsv40.2Az-Fe Engine Control System.Sfi System. Dtc P0100 Mass Or Volume Air Flow Circuit

  1. Disconnect the C2 MAF meter connector.

  1. Disconnect the C24 ECM connector.

  1. Measure the resistance between the terminals of the wire harness side connectors.

    Standard resistance (Check for open):
    Tester Connection
    		Specified Condition
    VG (C2-5) - VG (C24-118)
    		Below 1 Ω
    E2G (C2-4) - E2G (C24-116)
    Standard resistance (Check for short):
    Tester Connection
    		Specified Condition
    VG (C2-5) or VG (C24-118) - Body ground
    		10 kΩ or higher

  1. Reconnect the MAF meter connector.

  1. Reconnect the ECM connector.



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

REPLACE ECM