DTC    13    Evaporator Temperature Sensor Circuit

for Preparation Click here


DESCRIPTION

The No. 1 cooler thermistor is installed on the evaporator in the air conditioning unit. It detects the temperature of the cooled air that has passed through the evaporator which is then used in air conditioning control. The resistance of the No. 1 cooler thermistor changes in accordance with the temperature of the cooled air 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 thermistor is used for frost prevention.

DTC Code
DTC Detection Condition
Trouble Area
13
An open or short in evaporator temperature sensor circuit
  1. No. 1 cooler thermistor
  2. Air conditioning amplifier assembly
  3. Harness or connector

WIRING DIAGRAM


E227735E03


INSPECTION PROCEDURE

1.CHECK AIR CONDITIONING AMPLIFIER ASSEMBLY


    E225456E17

  1. Remove the air conditioning amplifier assembly with its connectors still connected (Click here).

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

    Standard Voltage:
    Tester Connection
    		Condition
    		Specified Condition
    A37-1 (TE) - A37-14 (SG-4)
    1. Ignition switch ON
    2. Evaporator temperature 0°C (32°F)
    		2.0 to 2.4 V
    1. Ignition switch ON
    2. Evaporator temperature 15°C (59°F)
    		1.4 to 1.8 V
    Text in Illustration 
    *a
    		Component with harness connected
    (Air Conditioning Amplifier Assembly)

    HINT:
    As the temperature increases, the voltage decreases.
    Result 
    Result
    		Proceed to
    OK (When troubleshooting according to problem symptoms table.)
    		A
    OK (When troubleshooting according to DTC.)
    		B
    NG
    		C


B
REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY (Click here)

C
Go to step 2
A

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

2.INSPECT NO. 1 COOLER THERMISTOR


    E170948E02

  1. Remove the No. 1 cooler thermistor (Click here).

  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
    Text in Illustration 
    *a
    		Resistance (kΩ)
    *b
    		Temperature

    NOTICE:
    1. Even slightly touching the No. 1 cooler thermistor may change the resistance value. Be sure to hold the connector of the No. 1 cooler thermistor.
    2. When measuring the resistance, the No. 1 cooler thermistor temperature must be the same as the ambient temperature.

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


NG
REPLACE NO. 1 COOLER THERMISTOR (Click here)
OK


3.CHECK HARNESS AND CONNECTOR (NO. 1 COOLER THERMISTOR - AIR CONDITIONING AMPLIFIER)

  1. Disconnect the A19 No. 1 cooler thermistor connector.

  1. Disconnect the A37 air conditioning amplifier assembly connector.

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    A37-1 (TE) - A19-1
    		Always
    		Below 1 Ω
    A37-14 (SG-4) - A19-2
    A37-1 (TE) - Body ground
    		Always
    		10 kΩ or higher
    A37-14 (SG-4) - Body ground


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY (Click here)