Inspection Procedure

WARNING: This page is about a different car, the 2008 Toyota RAV4. However, it is still accessible from the selected car via links, so may be relevant.

READ VALUE OF TECHSTREAM

Connect Techstream to the DLC3.
Turn the ignition switch ON and turn Techstream ON.

Select the item below in the Data List, and read the value displayed on Techstream.

Air conditioning amplifier

DATA LIST - AIR CONDITIONING AMPLIFIER

Item	Measurement Item / Display (Range)	Normal Condition	Diagnostic Note
Ambient Temp 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: 65.95X (150.71°F)

OK:

The display is as specified in the normal condition column.

Result

RESULT REFERENCE

Result	Proceed to
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: Go to next step

INSPECT AMBIENT TEMPERATURE SENSOR

Remove the ambient temperature sensor.

Measure the resistance of the sensor.

Standard resistance

RESISTANCE SPECIFICATION

Tester Connection	Condition	Specified Condition
1 - 2	10°C (50°F)	3.00 to 3.73 kΩ
1 - 2	15°C (50°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 ).

Fig 1: Ambient Temperature Sensor Resistance Graph

NG: REPLACE AMBIENT TEMPERATURE SENSOR

OK: Go to next step

CHECK WIRE HARNESS (AMBIENT TEMPERATURE SENSOR - COMBINATION METER)

Disconnect the A17 sensor connector.
Disconnect the E19 meter connector.

Fig 2: Identifying A17 And E19 Connector Terminals
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Measure the resistance of the wire harness side connectors.

Standard resistance

RESISTANCE SPECIFICATION

Tester Connection	Specified Condition
A17-2 (OT+) - E19-23 (TEMP)	Below 1 Ω
A17-1 (OT-) - E19-11 (TX1+)	Below 1 Ω
A17-2 (OT+) - Body ground	1 MΩ or higher
A17-1 (OT-) - Body ground	1 MΩ or higher

NG: REPAIR OR REPLACE HARNESS AND CONNECTOR

OK: REPLACE COMBINATION METER