The Mass Air Flow (MAF) meter uses a platinum hot wire. The mass air flow meter consists of a platinum hot wire, a temperature sensor and a control circuit installed in a plastic housing. The mass air flow meter hot wire and temperature sensor (located in the intake air by-pass of the housing) detect changes in the intake air temperature.

The hot wire is maintained at the predetermined temperature by controlling the current flow through the hot wire. This current flow is then used as the output voltage of the mass air flow meter.

The circuit is constructed so that the platinum hot wire and temperature sensor provide a bridge circuit, with the power transistor controlled so that the potential of A and B remains equal to maintain the predetermined temperature.

Dtc P0100 Mass Or Volume Air Flow Circuit. 1VD-FTV ENGINE CONTROL. Land Cruiser URJ200 URJ202 GRJ200 VDJ200

P0100
DTC Detection Drive Pattern	DTC Detection Condition	Trouble Area
Ignition switch ON for 3 seconds	Mass air flow (MAF) meter voltage is 0.2 V or less, or 4.9 V or more with the engine speed at 4000 rpm or less for 3 seconds (1 trip detection logic).	Open or short in Mass Air Flow (MAF) meter circuit Mass air flow meter ECM

P0102
DTC Detection Drive Pattern	DTC Detection Condition	Trouble Area
Ignition switch ON for 3 seconds	MAF meter voltage is 0.2 V or less with the engine speed at 4000 rpm or less for 3 seconds (1 trip detection logic).	Open in Mass Air Flow (MAF) meter circuit Mass air flow meter ECM

P0103
DTC Detection Drive Pattern	DTC Detection Condition	Trouble Area
Ignition switch ON for 3 seconds	MAF meter voltage is 4.9 V or more with the engine speed at 4000 rpm or less for 3 seconds (1 trip detection logic).	Shot in Mass Air Flow (MAF) meter circuit Mass air flow meter ECM

Related Data List
DTC No.	Data List
P0100	MAF
P0102
P0103

HINT:

If DTC P0100, and/or P0102 is stored, the following symptoms may appear (as the ECU mistakenly determines that there is less air than the actual intake air amount, EGR is decreased to match the target EGR):

Combustion noise worsens

If DTC P0100, and/or P0103 is stored, the following symptoms may appear (as the ECU mistakenly determines that there is more air than the actual intake air amount, EGR is increased to match the target EGR):

Misfire

White smoke

Black smoke

After confirming DTC P0100, P0102 or P0103, check the mass air flow ratio by entering the following menus: Powertrain / Engine / Data List / MAF.

Reference:
Air Flow Value (g/sec.)	Malfunction
Approximately 0.0	Open in mass air flow meter power source circuit Open or short in VG circuit
174.0 or more	Open in EVG circuit

WIRING DIAGRAM

Dtc P0100 Mass Or Volume Air Flow Circuit. 1VD-FTV ENGINE CONTROL. Land Cruiser URJ200 URJ202 GRJ200 VDJ200

INSPECTION PROCEDURE

NOTICE:

After replacing the ECM, the new ECM needs registration () and initialization ().

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

Connect the intelligent tester to the DLC3.

Start the engine and turn the tester on.

Enter the following menus: Powertrain / Engine / Data List / MAF.

Read the value.

Result
Result	Proceed to
0.0	A
174.0 or more	B
Between 1 and 173.0*	C

HINT:

*: The value should change when the throttle valve is opened or closed.

Go to step 8

Go to step 15

A

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

Dtc P0100 Mass Or Volume Air Flow Circuit. 1VD-FTV ENGINE CONTROL. Land Cruiser URJ200 URJ202 GRJ200 VDJ200

Disconnect the mass air flow meter connector.

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

Standard Voltage:
Tester Connection Switch Condition Specified Condition
C50-1 (+B) - Body ground Ignition switch ON 11 to 14 V

Go to step 5

OK

3.INSPECT MASS AIR FLOW METER

Inspect the mass air flow meter ().

Go to step 11

OK

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

Disconnect the mass air flow meter connector.

Disconnect the ECM connector.

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

Standard Resistance (Check for Open):
for LHD
Tester Connection Condition Specified Condition
C50-3 (VG) - C45-72 (VG) Always Below 1 Ω
C50-2 (E2G) - C45-118 (EVG) Always Below 1 Ω
for RHD
Tester Connection Condition Specified Condition
C50-3 (VG) - C46-72 (VG) Always Below 1 Ω
C50-2 (E2G) - C46-118 (EVG) Always Below 1 Ω

for LHD
Tester Connection	Condition	Specified Condition
C50-3 (VG) - C45-72 (VG)	Always	Below 1 Ω
C50-2 (E2G) - C45-118 (EVG)	Always	Below 1 Ω

for RHD
Tester Connection	Condition	Specified Condition
C50-3 (VG) - C46-72 (VG)	Always	Below 1 Ω
C50-2 (E2G) - C46-118 (EVG)	Always	Below 1 Ω

Standard Resistance (Check for Short):
for LHD
Tester Connection Condition Specified Condition
C50-3 (VG) or C45-72 (VG) - Body ground Always 10 kΩ or higher
for RHD
Tester Connection Condition Specified Condition
C50-3 (VG) or C46-72 (VG) - Body ground Always 10 kΩ or higher

for LHD
Tester Connection	Condition	Specified Condition
C50-3 (VG) or C45-72 (VG) - Body ground	Always	10 kΩ or higher

for RHD
Tester Connection	Condition	Specified Condition
C50-3 (VG) or C46-72 (VG) - Body ground	Always	10 kΩ or higher

Go to step 10

Go to step 12

5.INSPECT FUSE (EFI NO. 2)

Remove the EFI NO. 2 fuse from the engine room relay block.

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

Standard Resistance:
Tester Connection Condition Specified Condition
EFI NO. 2 fuse Always Below 1 Ω

Go to step 13

OK

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

Disconnect the mass air flow meter connector.

Remove the EFI NO. 2 fuse from the engine room relay block.

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

Standard Resistance (Check for Open):
Tester Connection Condition Specified Condition
C50-1 (+B) - EFI NO. 2 fuse (2) Always Below 1 Ω

Standard Resistance (Check for Short):
Tester Connection Condition Specified Condition
C50-1 (+B) or EFI NO. 2 fuse (2) - Body ground Always 10 kΩ or higher

Go to step 12

OK

7.CHECK HARNESS AND CONNECTOR (ENGINE ROOM RELAY BLOCK)

Remove the EFI NO. 2 fuse from the engine room relay block.

Remove the integration relay from the engine room relay block.

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

Standard Resistance (Check for Open):
Tester Connection Condition Specified Condition
EFI NO. 2 fuse (1) - 1B-4 Always Below 1 Ω

Standard Resistance (Check for Short):
Tester Connection Condition Specified Condition
EFI NO. 2 fuse (1) or 1B-4 - Body ground Always 10 kΩ or higher

Go to step 14

Go to step 12

8.CHECK HARNESS AND CONNECTOR (SENSOR GROUND)

Disconnect the mass air flow meter connector.

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

Standard Resistance (Check for Open):
Tester Connection Condition Specified Condition
C50-2 (E2G) - Body ground Always Below 1 Ω

Go to step 11

Go to step 9

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

Disconnect the mass air flow meter connector.

Disconnect the ECM connector.

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

Standard Resistance (Check for Open):
for LHD
Tester Connection Condition Specified Condition
C50-3 (VG) - C45-72 (VG) Always Below 1 Ω
C50-2 (E2G) - C45-118 (EVG) Always Below 1 Ω
for RHD
Tester Connection Condition Specified Condition
C50-3 (VG) - C46-72 (VG) Always Below 1 Ω
C50-2 (E2G) - C46-118 (EVG) Always Below 1 Ω

Standard Resistance (Check for Short):
for LHD
Tester Connection Condition Specified Condition
C50-3 (VG) or C45-72 (VG) - Body ground Always 10 kΩ or higher
for RHD
Tester Connection Condition Specified Condition
C50-3 (VG) or C46-72 (VG) - Body ground Always 10 kΩ or higher

Go to step 12

OK

10.REPLACE ECM

Replace the ECM ().

Go to step 15

11.REPLACE MASS AIR FLOW METER

Replace the mass air flow meter ().

Go to step 15

12.REPAIR OR REPLACE HARNESS OR CONNECTOR

Go to step 15

13.CHECK FOR SHORTS IN ALL HARNESSES AND CONNECTORS CONNECTED TO FUSE AND REPLACE FUSE

Go to step 15

14.CHECK ECM POWER SOURCE CIRCUIT

Check the ECM power source circuit ().

NEXT

15.CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED

Connect the intelligent tester to the DLC3.

Clear the DTCs ().

Turn the ignition switch off.

Turn the ignition switch to ON for 3 seconds

Enter the following menus: Powertrain / Engine / DTC.

Confirm that the DTC is not output again.

END

Tester Connection	Switch Condition	Specified Condition
C50-1 (+B) - Body ground	Ignition switch ON	11 to 14 V