- Cooler (duct sensor) thermistor (rear room temperature sensor)
- Harness or connector between cooler (duct sensor) thermistor (rear 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: RM000003F01000X |
| Title: HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM: DESCRIPTION (2008 Sequoia) | ||
|
DTC |
B1419/19 |
Rear Room Temperature Sensor Circuit |
DESCRIPTION
The cooler (duct sensor) thermistor (rear room temperature sensor) is installed in the rear panel to detect the rear room temperature and control the heater and air conditioner AUTO mode. The resistance of the cooler (duct sensor) thermistor (rear room temperature sensor) changes in accordance with the rear room temperature. As the temperature decreases, the resistance increases. As the temperature increases, the resistance decreases.
The air conditioning amplifier applies a voltage (5 V) to the cooler (duct sensor) thermistor (rear room temperature sensor) and reads voltage changes as changes in the resistance of the cooler (duct sensor) thermistor (rear room temperature sensor).
|
DTC Code |
DTC Detection Condition |
Trouble Area |
|---|---|---|
|
B1419/19 |
Open or short in rear room temperature sensor circuit |
|
WIRING DIAGRAM
INSPECTION PROCEDURE
PROCEDURE
|
1. |
READ VALUE USING TECHSTREAM (ROOM TEMP SENSOR (REAR)) |
(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 / Rear Temp Sensor (Rear).
(e) According to the display on the Techstream, read the Data List.
Air Conditioner
|
Tester Display |
Measurement Item/Range |
Normal Condition |
Diagnostic Note |
|---|---|---|---|
|
Rear Temp Sensor (Rear) |
Rear room temperature sensor / Min.: -6.5°C (20.3°F) Max.: 57.25°C (135.05°F) |
Actual rear room temperature is displayed |
Open circuit: -6.5°C (20.3°F) Short 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 |
|
|
2. |
INSPECT COOLER (DUCT SENSOR) THERMISTOR (REAR ROOM TEMPERATURE SENSOR) |
|
(a) Remove the cooler (duct sensor) thermistor (rear 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:
- Touching the sensor even slightly 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 (duct sensor) thermistor (rear room temperature sensor).
|
|
3. |
CHECK HARNESS AND CONNECTOR (REAR ROOM TEMPERATURE SENSOR - AIR CONDITIONING AMPLIFIER) |
|
(a) Disconnect the O15 cooler (duct sensor) thermistor (rear room temperature sensor) connector. |
(b) Disconnect the H67 air conditioning amplifier connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
O15-1 - H67-17 (TR) |
Always |
Below 1 Ω |
|
O15-2 - H67-7 (SG-6) |
Always |
Below 1 Ω |
|
O15-1 or H67-17 (TR) - Body ground |
Always |
10 kΩ or higher |
|
O15-2 or H67-7 (SG-6) - Body ground |
Always |
10 kΩ or higher |
(d) Reconnect the air conditioning amplifier connector.
(e) Reconnect the cooler (duct sensor) thermistor (rear room temperature sensor) connector.
|
|
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