Toyota Tundra. Manual — part 2395

Fig. 28: Identifying Recirculation / Fresh Switch
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

Air Conditioning Unit

AIR CONDITIONING UNIT REFERENCE

DTC B1411/11 ROOM TEMPERATURE SENSOR CIRCUIT

DESCRIPTION

The room temperature sensor is installed in the instrument panel to detect the room temperature and control the
heater and air conditioner "AUTO" mode. The resistance of the room temperature sensor changes in accordance
with the room temperature. As the temperature decreases, the resistance increases. As the temperature increases,
the resistance decreases.

The air conditioning amplifier applies voltage (5 V) to the room temperature sensor and reads voltage changes
as the resistance of the room temperature sensor changes. This sensor also sends the appropriate signals to the
air conditioning amplifier.

DTC DETECTION CONDITION CHART

Step

No.

Display

Code

Condition

Blower

Level

Air Mix

Damper

Airflow

Vent

Air Inlet Damper

Compressor

1

0

0

0% open

FACE

FRESH

OFF

2

1

1

0% open

FACE

FRESH

OFF

3

2

17

0% open

FACE

RECIRCULATION/FRESH

ON

4

3

17

0% open

FACE

RECIRCULATION

ON

5

4

17

50% open

B/L

RECIRCULATION

ON

6

5

17

50% open

B/L

RECIRCULATION

ON

7

6

17

50% open

FOOT

FRESH

ON

8

7

17

100% open FOOT-0

FRESH

ON

9

8

17

100% open

F/D

FRESH

ON

10

9

31

100% open

DEF

FRESH

ON

2009 Toyota Tundra

2009 HVAC Air Conditioning - Tundra

WIRING DIAGRAM

Fig. 29: Room Temperature Sensor - Wiring Diagram
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

INSPECTION PROCEDURE

1. READ VALUE USING TECHSTREAM (ROOM TEMPERATURE SENSOR)

a. Use the Data List to check if the room temperature sensor is functioning properly.

Air Conditioner

DATA LIST

OK:

The display is as specified in the normal condition.

DTC

DTC Detection Condition

Trouble Area

B1411/11

Open or short in room
temperature sensor circuit



Room temperature sensor



Harness and connector
between room temperature
sensor and air conditioning
amplifier



Air conditioning amplifier

Tester Display

Measurement Item/Range

Normal Condition

Diagnostic Note

Room Temperature

Sensor

Room temperature
sensor/Min.: -6.5°C (20.3°F)
Max.: 57.25°C (135.05°F)

Actual room
temperature is
displayed

Open in circuit: -6.5°C
(20.3°F)
Short in circuit: 57.25°
C (135.05°F)

2009 Toyota Tundra

2009 HVAC Air Conditioning - Tundra

Result

RESULT REFERENCE

B: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS
TABLE (See PROBLEM SYMPTOMS TABLE )

F: REPLACE AIR CONDITIONING AMPLIFIER (See REMOVAL )

A: Go to Next Step

2. INSPECT ROOM TEMPERATURE SENSOR

a. Remove the room temperature sensor (see REMOVAL ).

Result

Proceed to

NG

A

OK (Checking from the PROBLEM SYMPTOMS TABLE)

B

OK (Checking from the DTC)

C

2009 Toyota Tundra

2009 HVAC Air Conditioning - Tundra

Fig. 30: Temperature And Resistance Graph
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

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

Standard Resistance

TESTER CONNECTION SPECIFIED CONDITION CHART

Tester Connection Condition Specified Condition

1 - 2

10°C (50°F) 3.00 to 3.73 kohms
15°C (59°F) 2.45 to 2.88 kohms
20°C (68°F) 1.95 to 2.30 kohms
25°C (77°F) 1.60 to 1.80 kohms
30°C (86°F) 1.28 to 1.47 kohms
35°C (95°F) 1.00 to 1.22 kohms

40°C (104°F) 0.80 to 1.00 kohms

2009 Toyota Tundra

2009 HVAC Air Conditioning - Tundra