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 (AMBIENT TEMPERATURE SENSOR)

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 / Ambient Temperature Sensor
According to the display on tester, read the "Data List".

DATA LIST / AIR CONDITIONER

DATA LIST - AIR CONDITIONER

Item	Measurement Item/Range	Normal Condition	Diagnostic Note
Ambient Temperature Sensor	Ambient temperature sensor / Min.: -23.3°C (-9.94°F) Max.: 65.95°C(150.71°F)	Actual ambient temperature is displayed	Open circuit: -23.3°C (-9.94°F) Short circuit: 65.95°C (150.71 °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 output)	C

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

C: REPLACE AIR CONDITIONING AMPLIFIER

A: GO TO NEXT STEP

INSPECT AMBIENT TEMPERATURE SENSOR

Remove the ambient temperature sensor.

Measure the resistance.

Standard resistance

TESTER CONNECTION AND SPECIFIED CONDITION

Tester Connection	Condition	Specified Condition
1-2	10°C (50°F)	3.00 to 3.73 kΩ
1-2	15°C (59°F)	2.45 to 2.88 kΩ
1-2	20°C (68°F)	1.95 to 2.30 kΩ
1-2	25°C (77°F)	1.60 to 1.80 kΩ
1-2	30°C (86°F)	1.28 to 1.47 kΩ
1-2	35°C (95°F)	1.00 to 1.22 kΩ
1-2	40°C (104°F)	0.80 to 1.00 kΩ
1-2	45°C (113°F)	0.65 to 0.85 kΩ
1-2	50°C (122°F)	0.50 to 0.70 kΩ
1-2	55°C(131°F)	0.44 to 0.60 kΩ
1-2	60°C (140°F)	0.36 to 0.50 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 on the left).

Reinstall the ambient temperature sensor.

Fig 1: Identifying Ambient Temperature Sensor Connector Terminals And Graph

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: REPLACE AMBIENT TEMPERATURE SENSOR

OK: GO TO NEXT STEP

CHECK HARNESS AND CONNECTOR (AMBIENT TEMPERATURE SENSOR - AIR CONDITIONING AMPLIFIER)

Disconnect the B5 ambient temperature sensor connector.
Disconnect the E8 air conditioning amplifier connector.

Measure the resistance.

Standard resistance

TESTER CONNECTION AND SPECIFIED CONDITION

Tester Connection	Specified Condition
B5-1-E8-11 (SG-1)	Below 1 Ω
B5-2 - E8-5 (TAM)	Below 1 Ω
B5-1 - Body ground	10 kΩ or higher
B5-2 - Body ground	10 kΩ or higher

Reconnect the ambient temperature sensor connector.
Reconnect the air conditioning amplifier connector.

Fig 2: Identifying B5 Ambient Temperature Sensor Connector Terminals

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: REPLACE AIR CONDITIONING AMPLIFIER