Dtc B1413/13 Evaporator Temperature Sensor Circuit

Heater & Air Conditioning System. Lexus Gs430, Gs300. Uzs190 Grs190
Air Conditioning. Lexus Gs430, Gs300. Uzs190 Grs190

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

READ VALUE OF INTELLIGENT TESTER

INSPECT AIR CONDITIONING HARNESS

DTC B1413/13 Evaporator Temperature Sensor Circuit


DESCRIPTION

The evaporator temperature sensor (A/C 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 the appropriate signals to the A/C amplifier. The resistance of the evaporator temperature sensor (A/C 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 A/C amplifier applies voltage (5 V) to the evaporator temperature sensor (A/C thermistor) and reads voltage changes as the resistance of the evaporator temperature sensor (A/C thermistor) changes. 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. Air conditioning harness (evaporator temperature sensor)
  2. A/C amplifier

WIRING DIAGRAM


Lexus Gs430, Gs300. Uzs190 Grs190.Air Conditioning.Air Conditioning System. Dtc B1413/13 Evaporator Temperature Sensor Circuit


INSPECTION PROCEDURE

1.READ VALUE OF INTELLIGENT TESTER

  1. Connect the intelligent tester to the DLC3.

  1. Turn the engine switch on (IG) and push the intelligent tester main switch on.

  1. Select the item below in the Data List, and read the display on the intelligent tester.

    A/C amplifier:
    Item
    		Measurement Item / Display
    (Range)
    		Normal Condition
    		Diagnostic Note
    Evaporator temperature sensor
    (Evap Temp)
    		Evaporator temperature sensor /
    Min.: -29.7°C (-21.46°F)
    Max.: 59.55°C (139.019°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:
    NG
    		A
    OK (Checking from the PROBLEM SYMPTOMS TABLE)
    		B
    OK (Checking from the DTC)
    		C


B
PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE

C
REPLACE AIR CONDITIONING AMPLIFIER
A


2.INSPECT AIR CONDITIONING HARNESS
Lexus Gs430, Gs300. Uzs190 Grs190.Air Conditioning.Air Conditioning System. Dtc B1413/13 Evaporator Temperature Sensor Circuit

  1. Remove the air conditioning harness (evaporator temperature sensor).

  1. Measure the resistance of the harness.

    Standard resistance:
    Tester Connection
    		Condition
    		Specified Condition
    5 - 6
    		-10°C (14°F)
    		7.30 to 9.10 kΩ
    5 - 6
    		-5°C (23°F)
    		5.65 to 6.95 kΩ
    5 - 6
    		0°C (32°F)
    		4.40 to 5.35 kΩ
    5 - 6
    		5°C (41°F)
    		3.40 to 4.15 kΩ
    5 - 6
    		10°C (50°F)
    		2.70 to 3.25 kΩ
    5 - 6
    		15°C (59°F)
    		2.14 to 2.58 kΩ
    5 - 6
    		20°C (68°F)
    		1.71 to 2.05 kΩ
    5 - 6
    		25°C (77°F)
    		1.38 to 1.64 kΩ
    5 - 6
    		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).


NG
REPLACE AIR CONDITIONING HARNESS
OK

REPLACE AIR CONDITIONING AMPLIFIER