1Vd-Ftv Engine Control. Dtc P0112 Intake Air Temperature Circuit Low Input

The intake air temperature sensor is built into the mass air flow meter and detects the intake air temperature.
A thermistor built into 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 intake air temperature sensor is connected to the ECM.
The 5 V power source voltage from the ECM is applied to the intake air temperature sensor from terminal THA via resistor R.
Resistor R and the intake air temperature sensor are connected in series. When the resistance value of the intake air temperature sensor changes in accordance with the intake air temperature, the voltage at terminal THA also changes. Based on this signal, the ECM increases the fuel injection volume to improve driveability with a cold engine.
Land Cruiser. Urj200, 202 Grj200 Vdj200.1Vd-Ftv Engine Control.Ecd System (W/ Dpf).
Dtc
P0112 Intake Air Temperature Circuit Low Input

Land Cruiser. Urj200, 202 Grj200 Vdj200.1Vd-Ftv Engine Control.Ecd System (W/ Dpf).
Dtc
P0112 Intake Air Temperature Circuit Low Input

P0112
DTC Detection Drive Pattern	DTC Detection Condition	Trouble Area
Ignition switch ON for 0.5 seconds	Short in the intake air temperature sensor for 0.5 seconds (1 trip detection logic).	Short in intake air temperature sensor circuit Intake air temperature sensor (built into mass air flow meter) ECM

P0113
DTC Detection Drive Pattern	DTC Detection Condition	Trouble Area
Ignition switch ON for 0.5 seconds	Open in the intake air temperature sensor for 0.5 seconds (1 trip detection logic).	Open in intake air temperature sensor circuit Intake air temperature sensor (built into mass air flow meter) ECM

Related Data List
DTC No.	Data List
P0112 P0113	Intake Air

HINT:

If DTC P0112 and/or P0113 is stored, the following symptoms may appear:

Misfire
Combustion noise
Black smoke
White smoke
Lack of power

When DTC P0112 or P0113 is stored, check the intake air temperature by entering the following menus: Engine and ECT / Data List / Intake Air.

Reference
Temperature Displayed
Malfunction
-40°C (-40°F)
Open circuit
140°C (284°F) or higher
Short circuit

Reference
Temperature Displayed	Malfunction
-40°C (-40°F)	Open circuit
140°C (284°F) or higher	Short circuit

WIRING DIAGRAM

INSPECTION PROCEDURE

NOTICE:

After replacing the ECM, the new ECM needs registration (Click here) and initialization (Click here).
After replacing the fuel supply pump assembly, the ECM needs initialization (Click here).
After replacing an injector assembly, the ECM needs registration (Click here).

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)

Connect the GTS to the DLC3.

Turn the ignition switch to ON and turn the GTS on.

Enter the following menus: Engine and ECT / Data List / Intake Air.

Read the value.
OK:
Same as actual intake air temperature

Result
Result
Proceed to
-40°C (-40°F)
A
140°C (284°F) or higher
B
OK (same as actual intake air temperature)
C
HINT:
1. If there is an open circuit, the GTS indicates -40°C (-40°F).
2. If there is a short circuit, the GTS indicates 140°C (284°F) or higher.

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

Go to step 4

Go to step 11

A

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

Disconnect the mass air flow meter connector.

Connect terminals 4 (THA) and 5 (E2) of the mass air flow meter wire harness side connector.

Connect the GTS to the DLC3.

Turn the ignition switch to ON and turn the GTS on.

Enter the following menus: Engine and ECT / Data List / Intake Air.

Read the value.
OK:
140°C (284°F) or higher
Text in Illustration
*1
Mass air flow meter
*2
ECM
*a
Front view of wire harness connector
(to Mass Air Flow Meter)

Text in Illustration
*1	Mass air flow meter
*2	ECM
*a	Front view of wire harness connector (to Mass Air Flow Meter)

Go to step 7

Go to step 3

3.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:

for LHD
Tester Connection
Condition
Specified Condition
C50-4 (THA) - C45-115 (THA)
Always
Below 1 Ω
C50-5 (E2) - C45-92 (E2)
Always
Below 1 Ω

Standard Resistance:

for RHD
Tester Connection
Condition
Specified Condition
C50-4 (THA) - C46-115 (THA)
Always
Below 1 Ω
C50-5 (E2) - C46-92 (E2)
Always
Below 1 Ω

for LHD
Tester Connection	Condition	Specified Condition
C50-4 (THA) - C45-115 (THA)	Always	Below 1 Ω
C50-5 (E2) - C45-92 (E2)	Always	Below 1 Ω

for RHD
Tester Connection	Condition	Specified Condition
C50-4 (THA) - C46-115 (THA)	Always	Below 1 Ω
C50-5 (E2) - 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 mass air flow meter connector.

Connect the GTS to the DLC3.

Turn the ignition switch to ON and turn the GTS on.

Enter the following menus: Engine and ECT / Data List / Intake Air.

Read the value.
OK:
-40°C (-40°F)
Text in Illustration
*1
Mass Air Flow Meter
*2
ECM

Text in Illustration
*1	Mass Air Flow Meter
*2	ECM

Go to step 10

Go to step 5

5.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:

for LHD
Tester Connection
Condition
Specified Condition
C50-4 (THA) or C45-115 (THA) - Body ground
Always
10 kΩ or higher

Standard Resistance:

for RHD
Tester Connection
Condition
Specified Condition
C50-4 (THA) or C46-115 (THA) - Body ground
Always
10 kΩ or higher

for LHD
Tester Connection	Condition	Specified Condition
C50-4 (THA) or C45-115 (THA) - Body ground	Always	10 kΩ or higher

for RHD
Tester Connection	Condition	Specified Condition
C50-4 (THA) or C46-115 (THA) - Body ground	Always	10 kΩ or higher

Go to step 8

OK

6.REPLACE ECM

Replace the ECM (Click here).

Go to step 11

7.CONFIRM GOOD CONNECTION TO SENSOR. IF OK, REPLACE MASS AIR FLOW METER.

Replace the mass air flow meter (Click here).

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 (Click here).

Go to step 11

10.REPLACE MASS AIR FLOW METER

Replace the mass air flow meter (Click here).

NEXT

11.CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED

Connect the GTS to the DLC3.

Clear the DTCs (Click here).

Turn the ignition switch to ON for 1 second.

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

Confirm that the DTC is not output again.

END