- Cooler thermistor (front room temperature sensor)
- Harness or connector between cooler thermistor (front room temperature sensor) and air conditioning amplifier
- Air conditioning amplifier
| Last Modified: 11-29-2007 | 1.6 C | |
| Service Category: Vehicle Interior | Section: Heating/Air Conditioning | |
| Model Year: 2008 | Model: Sequoia | Doc ID: RM000002VXB002X |
| Title: HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM: DESCRIPTION (2008 Sequoia) | ||
|
DTC |
B1411/11 |
Room Temperature Sensor Circuit |
DESCRIPTION
The cooler thermistor (front 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 cooler thermistor (front 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 cooler thermistor (front room temperature sensor) and reads voltage changes as the resistance of the cooler thermistor (front room temperature sensor) changes. This sensor also sends the appropriate signals to the air conditioning amplifier.
|
DTC Code |
DTC Detection Condition |
Trouble Area |
|---|---|---|
|
B1411/11 |
Open or short in room temperature sensor circuit |
|
WIRING DIAGRAM
INSPECTION PROCEDURE
PROCEDURE
|
1. |
READ VALUE USING TECHSTREAM (ROOM TEMPERATURE SENSOR) |
(a) Connect the Techstream to the DLC3.
(b) Turn the ignition switch to ON.
(c) Turn the Techstream on.
(d) Enter the following menus: Body Electrical / Air Conditioner / Data List / Room Temperature Sensor.
(e) According to the display on the Techstream, read the Data List.
Air Conditioner
|
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) |
OK:
The display is as specified in the normal condition.
Result
|
Result |
Proceed to |
|---|---|
|
NG |
A |
|
OK (When troubleshooting according to Problem Symptoms Table) |
B |
|
OK (When troubleshooting according to the DTC output) |
C |
|
|
4. |
INSPECT COOLER THERMISTOR (FRONT ROOM TEMPERATURE SENSOR) |
|
(a) Remove the cooler thermistor (front room temperature sensor)
|
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
1 - 2 |
10°C (50°F) |
3.00 to 3.73 kΩ |
|
15°C (59°F) |
2.45 to 2.88 kΩ |
|
|
20°C (68°F) |
1.95 to 2.30 kΩ |
|
|
25°C (77°F) |
1.60 to 1.80 kΩ |
|
|
30°C (86°F) |
1.28 to 1.47 kΩ |
|
|
35°C (95°F) |
1.00 to 1.22 kΩ |
|
|
40°C (104°F) |
0.80 to 1.00 kΩ |
|
|
45°C (113°F) |
0.65 to 0.85 kΩ |
|
|
50°C (122°F) |
0.50 to 0.70 kΩ |
|
|
55°C (131°F) |
0.44 to 0.60 kΩ |
|
|
60°C (140°F) |
0.36 to 0.50 kΩ |
HINT:
- Even slightly touching the sensor may change the resistance value. Be sure to hold the connector of the sensor.
- When measuring, the sensor temperature must be the same as the ambient temperature.
- As the temperature increases, the resistance decreases (See the graph).
(c) Reinstall the cooler thermistor (front room temperature sensor).
|
|
6. |
CHECK HARNESS AND CONNECTOR (ROOM TEMPERATURE SENSOR - AIR CONDITIONING AMPLIFIER) |
|
(a) Disconnect the H16 cooler thermistor (front room temperature sensor) connector. |
(b) Disconnect the H24 air conditioning amplifier connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
H16-1 - H24-29 (TR) |
Always |
Below 1 Ω |
|
H16-2 - H24-34 (SG-1) |
Always |
Below 1 Ω |
|
H16-1 or H24-29 (TR) - Body ground |
Always |
10 kΩ or higher |
|
H16-2 or H24-34 (SG-1) - Body ground |
Always |
10 kΩ or higher |
(d) Reconnect the air conditioning amplifier connector.
(e) Reconnect the cooler thermistor (front room temperature sensor) connector.
|
|
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