Dtc P0102 Mass Or Volume Air Flow Circuit Low Input


DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

INSPECT MASS AIR FLOW METER (POWER SOURCE CIRCUIT)

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

CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ENGINE ROOM RELAY BLOCK)

REPAIR OR REPLACE HARNESS OR CONNECTOR

CHECK ECM POWER SOURCE CIRCUIT

REPLACE MASS AIR FLOW METER

CHECK WHETHER DTC OUTPUT RECURS

REPLACE ECM

CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED

DTC P0102 Mass or Volume Air Flow Circuit Low Input

DTC P0103 Mass or Volume Air Flow Circuit High Input


DESCRIPTION

The intake mass air flow meter assembly consists of a platinum hot wire, temperature sensor and control circuit installed in a plastic housing. The temperature sensor (located in the intake air by-pass of the housing) detects the intake air temperature.
There is little variation in the output from the intake mass air flow meter assembly, as it is hardly affected by the resistance of the wire harness.
The internal circuit of the intake mass air flow meter assembly contains a hot wire and cold wire. A voltage is output through a bridge circuit (refer to the illustration) indicating the cooling of the hot wire according to the intake air amount. This voltage is then converted into a periodic signal by the periodic signal conversion circuit and output to the ECM. The frequency varies between approximately 1945 and 8500 Hz depending on the air flow rate. The ECM calculates the mass air flow rate based on this frequency.

Land Cruiser, Land Cruiser Prado. Grj150 Trj150,155 Kdj150,155 Lj150, Gdj150,155.1Kd-Ftv Engine Control.Ecd System. Dtc P0102 Mass Or Volume Air Flow Circuit Low Input


P0102
DTC Detection Drive Pattern
DTC Detection Condition
Trouble Area
3 seconds after engine is started
Mass air flow meter signal frequency is less than 85 Hz with the engine speed at 5000 rpm or less 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
DTC Detection Drive Pattern
DTC Detection Condition
Trouble Area
3 seconds after engine is started
Mass air flow meter signal frequency is more than 9800 Hz with the engine speed at 5000 rpm or less for 3 seconds (1 trip detection logic).
  1. Open or short in Mass air flow meter circuit
  2. Mass air flow meter
  3. ECM

Related Data List
DTC No.
Data List
P0102
MAF
P0103
HINT:
  1. If DTC P0102 is stored, the following symptoms may appear (as the ECM mistakenly determines that there is less air than the actual intake air amount, EGR is decreased according to the target EGR):
    1. Combustion noise worsens
  2. If DTC P0103 is stored, the following symptoms may appear (as the ECM mistakenly determines that there is more air than the actual intake air amount, EGR is increased according to the target EGR):
    1. Misfire
    2. White smoke
    3. Black smoke

WIRING DIAGRAM


Land Cruiser, Land Cruiser Prado. Grj150 Trj150,155 Kdj150,155 Lj150, Gdj150,155.1Kd-Ftv Engine Control.Ecd System. Dtc P0102 Mass Or Volume Air Flow Circuit Low Input


INSPECTION PROCEDURE

NOTICE:
  1. Inspect the fuses of circuits related to this system before performing the following inspection procedure.
  2. After replacing the ECM, the new ECM needs registration (LandCruiser RM0000012XK0ARX.html) and initialization (LandCruiser RM000000TIN08CX.html).
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, and other data from the time the malfunction occurred.
1.INSPECT MASS AIR FLOW METER (POWER SOURCE CIRCUIT)
Land Cruiser, Land Cruiser Prado. Grj150 Trj150,155 Kdj150,155 Lj150, Gdj150,155.1Kd-Ftv Engine Control.Ecd 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
    C33-3 (+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)

  1. Reconnect the mass air flow meter connector.



NG
Go to step 3
OK


2.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 (Check for Open):
    Tester Connection
    		Condition
    		Specified Condition
    C33-5 (VG) - C90-17 (VG)
    		Always
    		Below 1 Ω
    C33-4 (E2G) - C90-18 (EVG)
    		Always
    		Below 1 Ω
    Standard Resistance (Check for Short):
    Tester Connection
    		Condition
    		Specified Condition
    C33-5 (VG) or C90-17 (VG) - Body ground
    		Always
    		10 kΩ or higher

  1. Reconnect the mass air flow meter connector.

  1. Reconnect the ECM connector.



OK
Go to step 6

NG
Go to step 4

3.CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ENGINE ROOM RELAY BLOCK)

  1. Disconnect the mass air flow meter connector.

  1. Remove the No. 1 integration relay from the engine room 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
    C33-3 (+B) - 1B-4
    		Always
    		Below 1 Ω
    Standard Resistance (Check for Short):
    Tester Connection
    		Condition
    		Specified Condition
    C33-3 (+B) or 1B-4 - Body ground
    		Always
    		10 kΩ or higher

  1. Reconnect the mass air flow meter connector.

  1. Reinstall the No. 1 integration relay.



OK
Go to step 5

NG
Go to step 4

4.REPAIR OR REPLACE HARNESS OR CONNECTOR

  1. Repair or replace the harness or connector.



NEXT
Go to step 9

5.CHECK ECM POWER SOURCE CIRCUIT

  1. Check the ECM power source circuit (LandCruiser RM000000TI20AJX.html).



NEXT
Go to step 9

6.REPLACE MASS AIR FLOW METER

  1. Replace the mass air flow meter (LandCruiser RM000000VHD05OX.html).


NEXT


7.CHECK WHETHER DTC OUTPUT RECURS

  1. Connect the intelligent tester to the DLC3.

  1. Clear the DTCs (LandCruiser RM000000PDK1DJX.html).

  1. Start the engine and wait for 3 seconds or more.

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

  1. Read the DTCs.

    Result
    Result
    		Proceed to
    P0102 or P0103
    		A
    No output
    		B


B
END
A


8.REPLACE ECM

  1. Replace the ECM (LandCruiser RM0000013Z002CX.html).


NEXT


9.CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED

  1. Connect the intelligent tester to the DLC3.

  1. Clear the DTCs (LandCruiser RM000000PDK1DJX.html).

  1. Start the engine and wait for 3 seconds or more.

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

  1. Confirm that the DTC is not output again.


NEXT

END