Toyota Venza: Evaporator Temperature Sensor Circuit (B1413/13)

Toyota Venza Service Manual / Heating / Air Conditioning / Air Conditioning System / Evaporator Temperature Sensor Circuit (B1413/13)

DESCRIPTION

The evaporator temperature sensor is installed on the evaporator in the air conditioning unit to detect the cooled air temperature that has passed through the evaporator and to control the air conditioning. It sends appropriate signals to the A/C amplifier. The resistance of the 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 A/C amplifier applies voltage (5 V) to the evaporator temperature sensor and reads voltage changes as the resistance of the evaporator temperature sensor 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	Evaporator temperature sensor Air conditioning harness A/C amplifier

WIRING DIAGRAM

PROCEDURE

1.	READ VALUE USING TECHSTREAM

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(d) Enter the following menus: Body / Air Conditioner / Data List.

(e) Check the value(s) by referring to the table below.

Air Conditioner

Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
Evaporator Fin Thermistor	Evaporator temperature sensor / Min.: -30°C (-22°F) Max.: 59.6°C (139.28°F)	Actual evaporator temperature displayed	-

Tester Display

Measurement Item/Range

Normal Condition

Diagnostic Note

Evaporator Fin Thermistor

Evaporator temperature sensor /

Min.: -30°C (-22°F)

Max.: 59.6°C (139.28°F)

Actual evaporator temperature displayed

OK:

The display is as specified in the Normal Condition column.

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

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

REPLACE A/C AMPLIFIER

2.	INSPECT EVAPORATOR TEMPERATURE SENSOR

(a) Remove the evaporator temperature sensor.

(b) Disconnect the evaporator temperature sensor connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
e2-1 - e2-2	-10°C (14°F)	7.30 to 9.10 kΩ
e2-1 - e2-2	-5°C (23°F)	5.65 to 6.95 kΩ
e2-1 - e2-2	0°C (32°F)	4.40 to 5.35 kΩ
e2-1 - e2-2	5°C (41°F)	3.40 to 4.15 kΩ
e2-1 - e2-2	10°C (50°F)	2.70 to 3.25 kΩ
e2-1 - e2-2	15°C (59°F)	2.14 to 2.58 kΩ
e2-1 - e2-2	20°C (68°F)	1.71 to 2.05 kΩ
e2-1 - e2-2	25°C (77°F)	1.38 to 1.64 kΩ
e2-1 - e2-2	30°C (86°F)	1.11 to 1.32 kΩ

NOTICE:

Hold the sensor only by its connector. Touching the sensor may change the resistance value.
When measuring, the sensor temperature must be the same as the ambient temperature.

HINT:

As the temperature increases, the resistance decreases (see the graph).

Text in Illustration

Component without harness connected

(Evaporator Temperature Sensor)

Sensing Portion

REPLACE EVAPORATOR TEMPERATURE SENSOR

3.	INSPECT AIR CONDITIONING HARNESS (A/C AMPLIFIER - EVAPORATOR TEMPERATURE SENSOR)

(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
z7-6 (TEA) - e2-2	Always	Below 1 Ω
z7-5 (SGA) - e2-1	Always	Below 1 Ω
z7-6 (TEA) - Body ground	Always	10 kΩ or higher
z7-5 (SGA) - Body ground	Always	10 kΩ or higher

Text in Illustration

Front view of wire harness connector

(to A/C Amplifier)

Front view of wire harness connector

(to Evaporator Temperature Sensor)

REPLACE A/C AMPLIFIER

REPLACE AIR CONDITIONING HARNESS

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