Inspection Procedure

WARNING: This page is about a different car, the 2008 Toyota Yaris. However, it is still accessible from the selected car via links, so may be relevant.

READ VALUE USING TECHSTREAM (EVAPORATOR FIN THERMISTOR)

Connect a Techstream to the DLC3.
Turn the ignition switch to ON.
Turn the tester on.
Enter the following menus: Body Electrical / Air Conditioner / Data List / Evaporator Fin Thermistor
According to the display on tester, read the "Data List".

DATA LIST / AIR CONDITIONER

DIAGNOSTIC NOTE AND MEASUREMENT ITEM / DISPLAY RANGE

Item	Measurement Item / Display (Range)	Normal Condition	Diagnostic Note
Evaporator Fin Thermistor	Evaporator fin thermistor / 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 REFERENCE

Result	Proceed to
NG	A
OK (When troubleshooting according to PROBLEM SYMPTOMS TABLE )	B
OK (When troubleshooting according to the DTC)	C

B: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE

C: REPLACE AIR CONDITIONING AMPLIFIER

A: GO TO NEXT STEP

INSPECT NO. 1 COOLER THERMISTOR (EVAPORATOR TEMPERATURE SENSOR)

Remove the evaporator temperature sensor.

Measure the resistance.

Standard resistance

TESTER CONNECTION AND SPECIFIED CONDITION

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

NOTE:

Touching the sensor even slightly 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.

HINT:

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

Reinstall the evaporator temperature sensor.

Fig 1: Identifying No. 1 Cooler Thermistor And Temperature Graph

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Result

RESULT REFERENCE

Result	Proceed to
OK	A
NG (for Hatchback)	B
NG (for Sedan)	C

B: REPLACE NO. 1 COOLER THERMISTOR (EVAPORATOR TEMPERATURE SENSOR) (See DISASSEMBLY )

C: REPLACE NO. 1 COOLER THERMISTOR (EVAPORATOR TEMPERATURE SENSOR) (See DISASSEMBLY )

A: GO TO NEXT STEP

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

Disconnect the E2 No. 1 cooler thermistor (evaporator temperature sensor) connector.
Disconnect the E8 air conditioning amplifier connector.

Measure the resistance.

Standard resistance

TESTER CONNECTION AND SPECIFIED CONDITION

Tester Connection	Specified Condition
E2-2-E8-10(TE)	Below 1 Ω
E2-1 - E8-4 (SG-2)	Below 1 Ω
E2-2 - Body ground	10 kΩ or higher
E2-1 - Body ground	10 kΩ or higher

Reconnect the No. 1 cooler thermistor connector.
Reconnect the air conditioning amplifier connector.

Fig 2: Identifying E2 No. 1 Cooler Thermistor

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: REPLACE AIR CONDITIONING AMPLIFIER