DESCRIPTION
WIRING DIAGRAM
INSPECTION PROCEDURE
READ VALUE USING INTELLIGENT TESTER (NO. 1 COOLER THERMISTOR)
INSPECT NO. 1 COOLER THERMISTOR
DTC B1413/13 Evaporator Temperature Sensor Circuit
DESCRIPTION
The No. 1 cooler thermistor 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 assembly. The resistance of the No. 1 cooler thermistor 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 assembly applies voltage (5 V) to the No. 1 cooler thermistor and reads voltage changes as the resistance of the No. 1 cooler thermistor changes. This sensor is used for frost prevention.
| DTC Code | DTC Detection Condition | Trouble Area |
| B1413/13 |
An open or short in the No. 1 cooler thermistor circuit. |
No. 1 cooler thermistor
Air conditioning harness assembly (No. 1 cooler thermistor)
Air conditioning amplifier assembly
|
WIRING DIAGRAM
INSPECTION PROCEDURE
| 1.READ VALUE USING INTELLIGENT TESTER (NO. 1 COOLER THERMISTOR) |
Use the Data List to check if the No. 1 cooler thermistor is functioning properly.
Air Conditioner| Tester Display | Measurement Item/Range | Normal Condition | Diagnostic Note |
| Evaporator Fin Thermistor |
No. 1 cooler thermistor /
Min.: -29.7°C (-21.46°F)
Max.: 59.55°C (139.19°F) |
Actual evaporator temperature displayed |
Open in the circuit: -29.7°C (-21.46°F).
Short in the circuit: 59.55°C (139.19°F). |
- OK:
- The display is as specified in the normal condition.
| OK | |
| |
| REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY ()
|
|
| 2.INSPECT NO. 1 COOLER THERMISTOR |
Remove the No. 1 cooler thermistor.
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 |
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).
Result| Result | Proceed to |
| OK (for LHD) | A |
| OK (for RHD) | B |
| NG (for LHD) | C |
| NG (for RHD) | D |
| | REPLACE AIR CONDITIONING HARNESS ASSEMBLY ()
|
|
|
| | REPLACE NO. 1 COOLER THERMISTOR ()
|
|
|
| | REPLACE NO. 1 COOLER THERMISTOR ()
|
|
|
| A | |
| |
| REPLACE AIR CONDITIONING HARNESS ASSEMBLY ()
|
|
