- No. 1 cooler thermistor (evaporator temperature sensor)
- Air conditioning harness
- 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: RM000002VXD005X |
| Title: HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM: DESCRIPTION (2008 Sequoia) | ||
|
DTC |
B1413/13 |
Evaporator Temperature Sensor Circuit |
DESCRIPTION
The No. 1 cooler thermistor (evaporator temperature sensor) is installed on the evaporator in the air conditioner unit to detect the cooled air temperature that has passed through the evaporator and control the air conditioning. It sends appropriate signals to the air conditioning amplifier. The resistance of the No. 1 cooler thermistor (evaporator temperature sensor) changes in accordance with the cooled air temperature that has passed through the evaporator. As the temperature decreases, the resistance increases. As the temperature increases, the resistance decreases.
The air conditioning amplifier applies voltage (5 V) to the No. 1 cooler thermistor (evaporator temperature sensor) and reads voltage changes as the resistance of the No. 1 cooler thermistor (evaporator temperature sensor) changes. This sensor is used for frost prevention.
|
DTC Code |
DTC Detection Condition |
Trouble Area |
|---|---|---|
|
B1413/13 |
Open or short in evaporator temperature sensor circuit |
|
WIRING DIAGRAM
INSPECTION PROCEDURE
PROCEDURE
|
1. |
READ VALUE USING TECHSTREAM (EVAPORATOR FIN THERMISTOR) |
(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 / Evaporator Fin Thermistor.
(e) According to the display on the Techstream, read the Data List.
Air Conditioner
|
Tester Display |
Measurement Item/Range |
Normal Condition |
Diagnostic Note |
|---|---|---|---|
|
Evaporator Fin Thermistor |
Evaporator fin thermistor / Min.: -29.7°C (-21.46°F) Max.: 59.55°C (139.19°F) |
Actual evaporator temperature is displayed |
Open in circuit: -29.7°C (-21.46°F) Short in circuit: 59.55°C (139.19°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 NO. 1 COOLER THERMISTOR (EVAPORATOR TEMPERATURE SENSOR) |
(a) Remove the No. 1 cooler thermistor (evaporator temperature sensor) connector
.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
1 - 2 |
-10°C (14°F) |
7.30 to 9.10 kΩ |
|
-5°C (23°F) |
5.65 to 6.95 kΩ |
|
|
0°C (32°F) |
4.40 to 5.35 kΩ |
|
|
5°C (41°F) |
3.40 to 4.15 kΩ |
|
|
10°C (50°F) |
2.70 to 3.25 kΩ |
|
|
15°C (59°F) |
2.14 to 2.58 kΩ |
|
|
20°C (68°F) |
1.71 to 2.05 kΩ |
|
|
25°C (77°F) |
1.38 to 1.64 kΩ |
|
|
30°C (86°F) |
1.11 to 1.32 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 No. 1 cooler thermistor (evaporator temperature sensor) connector.
|
|
3. |
INSPECT AIR CONDITIONING HARNESS |
(a) Remove the air conditioning harness.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
1 (SGB) - 5 (SGA) |
Always |
Below 1 Ω |
|
2 (TEB) - 6 (TEA) |
Always |
Below 1 Ω |
|
1 (SGB) - 6 (TEA) |
Always |
10 kΩ or higher |
|
2 (TEB) - 5 (SGA) |
Always |
10 kΩ or higher |
(c) Reinstall the air conditioning harness.
|
|
|