DTC    B1413/13    Evaporator Temperature Sensor Circuit

for Preparation Click here


DESCRIPTION

The front evaporator temperature sensor (No. 1 cooler thermistor) is installed on the evaporator in the air conditioner unit to detect the temperature of the cooled air that has passed through the evaporator and to control the air conditioner. It sends signals to the air conditioning amplifier, which change in accordance with the resistance of the front evaporator temperature sensor (No. 1 cooler thermistor). 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 front evaporator temperature sensor (No. 1 cooler thermistor) and reads voltage changes as changes in the resistance of the front evaporator temperature sensor (No. 1 cooler thermistor). This sensor is used for frost prevention.

DTC No.
DTC Detection Condition
Trouble Area
B1413/13
Open or short in evaporator temperature sensor circuit
  1. Front evaporator temperature sensor (No. 1 cooler thermistor)
  2. Harness and connector between front evaporator temperature sensor (No. 1 cooler thermistor) and air conditioning amplifier
  3. Air conditioning amplifier

WIRING DIAGRAM


E147578E04


INSPECTION PROCEDURE

1.READ VALUE USING INTELLIGENT TESTER (EVAPORATOR FIN THERMISTOR)

  1. Connect the intelligent tester to the DLC3.

  1. Turn the ignition switch to ON.

  1. Turn the intelligent tester on.

  1. Enter the following menus: Body / Air Conditioner / Data List.

  1. According to the display on the intelligent tester, read the Data List.

    Air Conditioner 
    Item
    		Measurement Item/Display (Range)
    		Normal Condition
    		Diagnostic Note
    Evaporator Fin Thermistor
    		Evaporator temperature sensor / Min.: -29.7°C (-21.46°F)
    Max.: 59.55°C (139.019°F)
    		Actual evaporator temperature is displayed
    		Open circuit: -29.7°C (-21.46°F)
    Short circuit: 59.55°C (139.019°F)

    OK:
    The display is as specified in the normal condition column.


    Result 
    Result
    		Proceed to
    NG
    		A
    OK (When troubleshooting according to the Problem Symptoms Table)
    		B
    OK (When troubleshooting according to the DTC output)
    		C



B
PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE (Click here)

C
REPLACE AIR CONDITIONING AMPLIFIER (Click here)
A


2.INSPECT FRONT EVAPORATOR TEMPERATURE SENSOR (NO. 1 COOLER THERMISTOR)
E177531E01

  1. Remove the front evaporator temperature sensor (No. 1 cooler thermistor).

  1. 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

NOTICE:
  1. Even slightly touching the sensor may change the resistance value. Be sure to hold the connector of the sensor.
  2. When measuring, the sensor temperature must be the same as the ambient temperature.

HINT:
As the temperature increases, the resistance decreases (See the graph).

  1. Reinstall the front evaporator temperature sensor (No. 1 cooler thermistor).



NG
REPLACE FRONT EVAPORATOR TEMPERATURE SENSOR (NO. 1 COOLER THERMISTOR) (Click here)
OK


3.INSPECT AIR CONDITIONING HARNESS


    E177530E01

  1. Remove the air conditioning harness (Click here).

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    1 (SGB) - z1-5 (SG)
    		Always
    		Below 1 Ω
    2 (TEB) - z1-6 (TE)
    		Always
    		Below 1 Ω
    1 (SGB) - Body ground
    		Always
    		10 kΩ or higher
    2 (TEB) - Body ground
    		Always
    		10 kΩ or higher

  1. Reinstall the air conditioning harness.
    Text in Illustration 
    *1
    		Front view of wire harness connector
    (Air Conditioner Harness)
    *2
    		Front Evaporator Temperature Sensor (No. 1 Cooler Thermistor) Side
    *3
    		Air Conditioning Amplifier Side



NG
REPLACE AIR CONDITIONING HARNESS (Click here)
OK

REPLACE AIR CONDITIONING AMPLIFIER (Click here)