The Intake Air Temperature (IAT) sensor detects the IAT after the intake air passes through the intercooler. A built-in thermistor in the sensor changes its resistance value according to the intake air temperature. The lower the intake air temperature, the higher the thermistor resistance value. The higher the intake air temperature, the lower the thermistor resistance value (See Fig. 1).

The sensor is connected to the ECM. The 5 V power source voltage in the ECM is applied to the sensor from terminal THIA via resistor R. Resistor R and the sensor are connected in series. When the resistance value of the sensor changes in accordance with changes in the IAT, the potential at terminal THIA also changes. Based on this signal, the ECM corrects the fuel injection volume to improve driveability with a cold engine.

P007C
DTC Detection Drive Pattern	DTC Detection Condition	Trouble Area
Engine switch on (IG) for 1 second	Short in the intake air temperature sensor (turbo) circuit for 0.5 seconds (1 trip detection logic).	Short in intake air temperature sensor (turbo) circuit Intake air temperature sensor (turbo) ECM

P007D
DTC Detection Drive Pattern	DTC Detection Condition	Trouble Area
Engine switch on (IG) for 1 second	Open in the intake air temperature sensor (turbo) circuit for 0.5 seconds (1 trip detection logic).	Open in intake air temperature sensor (turbo) circuit Intake air temperature sensor (turbo) ECM

Related Data List
DTC No.	Data List
P007C P007D	Intake Air Temp (Turbo)

HINT:

If DTC P007C or P007D is stored, the following symptoms may appear:

Misfire

Combustion noise

Black smoke

White smoke

Lack of power

WIRING DIAGRAM

Dtc P007C Charge Air Cooler Temperature Sensor Circuit Low. 1VD-FTV ENGINE CONTROL. Land Cruiser URJ200 URJ202 GRJ200 VDJ200

INSPECTION PROCEDURE

NOTICE:

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

After replacing the fuel supply pump assembly, the ECM needs initialization ().

After replacing an injector assembly, the ECM needs registration ().

HINT:

Read freeze frame data using the GTS. 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 GTS (INTAKE AIR TEMPERATURE (TURBO))

Connect the GTS to the DLC3.

Turn the engine switch on (IG) and turn the GTS on.

Enter the following menus: Engine and ECT / Data List / Intake Air Temp (Turbo).

Read the value.

OK:
Same as air temperature near intake manifold

Result
Result	Proceed to
-40°C (-40°F)	A
140°C (284°F) or higher	B
OK (same as air temperature near intake manifold)	C

HINT:

If there is an open circuit, the GTS indicates -40°C (-40°F).

If there is a short circuit, the GTS indicates 140°C (284°F) or higher.

Go to step 4

Go to step 11

A

2.READ VALUE USING GTS (CHECK FOR OPEN IN WIRE HARNESS)

Disconnect the intake air temperature sensor (turbo) connector.

Connect terminals 1 and 2 of the intake air temperature sensor (turbo) wire harness side connector.

Connect the GTS to the DLC3.

Turn the engine switch on (IG) and turn the GTS on.

Enter the following menus: Engine and ECT / Data List / Intake Air Temp (Turbo).

Read the value.

OK:
140°C (284°F) or higher

Text in Illustration
*1	Intake Air Temperature Sensor (Turbo)
*2	ECM
*a	Front view of wire harness connector (to Intake Air Temperature Sensor (Turbo))

Go to step 7

Go to step 3

3.CHECK HARNESS AND CONNECTOR (INTAKE AIR TEMPERATURE SENSOR (TURBO) - ECM)

Disconnect the intake air temperature sensor (turbo) connector.

Disconnect the ECM connector.

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

Standard Resistance:
for LHD
Tester Connection Condition Specified Condition
C79-2 - C45-90 (THIA) Always Below 1 Ω
C79-1 - C45-92 (E2) Always Below 1 Ω

for LHD
Tester Connection	Condition	Specified Condition
C79-2 - C45-90 (THIA)	Always	Below 1 Ω
C79-1 - C45-92 (E2)	Always	Below 1 Ω

Standard Resistance:
for RHD
Tester Connection Condition Specified Condition
C79-2 - C46-90 (THIA) Always Below 1 Ω
C79-1 - C46-92 (E2) Always Below 1 Ω

for RHD
Tester Connection	Condition	Specified Condition
C79-2 - C46-90 (THIA)	Always	Below 1 Ω
C79-1 - C46-92 (E2)	Always	Below 1 Ω

Go to step 9

Go to step 8

4.READ VALUE USING GTS (CHECK FOR SHORT IN WIRE HARNESS)

Disconnect the intake air temperature sensor (turbo) connector.

Connect the GTS to the DLC3.

Turn the engine switch on (IG) and turn the GTS on.

Enter the following menus: Engine and ECT / Data List / Intake Air Temp (Turbo).

Read the value.

OK:
-40°C (-40°F)

Text in Illustration
*1	Intake Air Temperature Sensor (Turbo)
*2	ECM

Go to step 10

Go to step 5

5.CHECK HARNESS AND CONNECTOR (INTAKE AIR TEMPERATURE SENSOR (TURBO) - ECM)

Disconnect the intake air temperature sensor (turbo) connector.

Disconnect the ECM connector.

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

Standard Resistance:
for LHD
Tester Connection Condition Specified Condition
C79-2 or C45-90 (THIA) - Body ground Always 10 kΩ or higher

for LHD
Tester Connection	Condition	Specified Condition
C79-2 or C45-90 (THIA) - Body ground	Always	10 kΩ or higher

Standard Resistance:
for RHD
Tester Connection Condition Specified Condition
C79-2 or C46-90 (THIA) - Body ground Always 10 kΩ or higher

for RHD
Tester Connection	Condition	Specified Condition
C79-2 or C46-90 (THIA) - Body ground	Always	10 kΩ or higher

Go to step 8

OK

6.REPLACE ECM

Replace the ECM ().

Go to step 11

7.CONFIRM GOOD CONNECTION TO SENSOR. IF OK, REPLACE INTAKE AIR TEMPERATURE SENSOR (TURBO).

Replace the intake air temperature sensor (turbo) ().

Go to step 11

8.REPAIR OR REPLACE HARNESS OR CONNECTOR

Repair or replace the harness or connector.

Go to step 11

9.CONFIRM GOOD CONNECTION TO ECM. IF OK, REPLACE ECM.

Replace the ECM ().

Go to step 11

10.REPLACE INTAKE AIR TEMPERATURE SENSOR (TURBO)

Replace the intake air temperature sensor (turbo) ().

NEXT

11.CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED

Connect the GTS to the DLC3.

Clear the DTCs ().

Turn the engine switch off for 30 seconds or more.

Turn the engine switch on (IG) for 1 second.

Enter the following menus: Engine and ECT / Trouble Codes.

Confirm that the DTC is not output again.

END

1VD-FTV ENGINE CONTROL

Land Cruiser URJ200 URJ202 GRJ200 VDJ200

ECD SYSTEM w/ DPF