Toyota Tundra. Manual — part 1341

The ECM monitors the sensor voltage and uses this value to calculate the IAT. When the sensor output voltage
deviates from the normal operating range, the ECM interprets this as a malfunction in the IAT sensor and sets a
DTC.

Example:

If the sensor output voltage is more than 4.91 V for 0.5 seconds or more, the ECM determines that there is an
open in the IAT sensor circuit, and sets DTC P0113. Conversely, if the output voltage is less than 0.18 V for 0.5
seconds or more, the ECM determines that there is a short in the sensor circuit, and sets DTC P0112.

If the malfunction is not repaired successfully, a DTC is set 0.5 seconds after the engine is next started.

MONITOR STRATEGY

MONITOR STRATEGY

TYPICAL ENABLING CONDITIONS

TYPICAL ENABLING CONDITIONS

TYPICAL MALFUNCTION THRESHOLDS

P0110:

TYPICAL MALFUNCTION THRESHOLDS - P0110

P0112:

TYPICAL MALFUNCTION THRESHOLDS - P0112

P0113:

TYPICAL MALFUNCTION THRESHOLDS - P0113

Related DTCs

P0110: IAT sensor range check (Fluctuating)
P0112: IAT sensor range check (Low voltage)
P0113: IAT sensor range check (High voltage)

Required Sensors/Components (Main)

IAT sensor

Required Sensors/Components (Related)

-

Frequency of Operation

Continuous

Duration

0.5 seconds

MIL Operation

Immediate

Sequence of Operation

None

Monitor runs whenever following DTCs not present

None

IAT sensor voltage

Less than 0.18 V, or higher than 4.91 V

IAT sensor voltage [IAT]

Less than 0.18 V [More than 140°C (284°F)]

2008 Toyota Tundra

2008 ENGINE PERFORMANCE Engine Control System (2UZ-FE) - Tundra

COMPONENT OPERATING RANGE

COMPONENT OPERATING RANGE

WIRING DIAGRAM

Fig. 64: IAT Sensor - Wiring Diagram

INSPECTION PROCEDURE

HINT:

Read freeze frame data using the Techstream. 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, if the air-fuel ratio was lean or rich, and other data
from the time the malfunction occurred.

1. READ OUTPUT DTC

a. Connect the Techstream to the DLC3.

b. Turn the ignition switch to ON and turn the Techstream ON.

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

d. Read DTCs.

Result

RESULT REFERENCE

IAT sensor voltage [IAT]

Higher than 4.91 V [Less than -40°C (-40T)]

IAT sensor voltage [IAT]

0.18 to 4.91 V [-40 to 140°C (-40 to 284°F)]

Result

Proceed To

P0110 is output

A

P0112 is output

B

2008 Toyota Tundra

2008 ENGINE PERFORMANCE Engine Control System (2UZ-FE) - Tundra

B : Go to step 5

C : Go to step 3

A : Go To Next Step

2. READ VALUE USING TECHSTREAM (INTAKE AIR TEMPERATURE)

a. Connect the Techstream to the DLC3.

b. Turn the ignition switch to ON.

c. Turn the Techstream ON.

d. Enter the following menus: Powertrain/Engine and ECT/All Data/Intake Air.

e. Read the value displayed on the Techstream.

Standard:

Same as actual Intake Air Temperature (IAT).

Result

RESULT REFERENCE

HINT:



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



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

B : Go to step 5

C : CHECK FOR INTERMITTENT PROBLEMS (See CHECK FOR INTERMITTENT
PROBLEMS )

A : Go To Next Step

3. READ VALUE USING TECHSTREAM (CHECK FOR OPEN IN WIRE HARNESS)

a. Disconnect the D7 MAF meter connector.

b. Connect terminals 4 (THA) and 5 (E2) of the MAF meter wire harness side connector.

c. Connect the Techstream to the DLC3.

d. Turn the ignition switch to ON.

P0113 is output

C

Result

Proceed To

-40°C (-40°F)

A

140°C (284°F) or higher

B

Same as actual IAT

C

2008 Toyota Tundra

2008 ENGINE PERFORMANCE Engine Control System (2UZ-FE) - Tundra

e. Turn the Techstream ON.

f. Enter the following menus: Powertrain/Engine and ECT/All Data/Intake Air.

g. Read the value displayed on the Techstream.

Standard value:

140°C (284°F) or higher

Fig. 65: Connecting Terminals 4 (THA) & 5 (E2) Of D7 MAF Meter Wire Harness Side
Connector

NG : Go to step 4

OK : CONFIRM GOOD CONNECTION TO SENSOR. IF OK, REPLACE MASS AIR FLOW
METER (See REMOVAL )

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

a. Disconnect the D7 MAF meter connector.

b. Disconnect the D74 ECM connector.

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

Standard resistance

STANDARD RESISTANCE SPECIFICATION

Tester Connection

Condition Specified Condition

D7-4 (THA) - D74-73 (THA) Always

Below 1 ohms

D7-5 (E2) - D74-97 (ETHW)

Always

Below 1 ohms

2008 Toyota Tundra

2008 ENGINE PERFORMANCE Engine Control System (2UZ-FE) - Tundra