Inspection Procedure

WARNING: This page is about a different car, the 2007 Toyota RAV4. However, it is still accessible from the selected car via links, so may be relevant.

READ VALUE OF INTELLIGENT TESTER (ROOM TEMP)

Connect the intelligent tester (with CAN VIM) to the DLC3.
Turn the ignition switch ON and turn the intelligent tester main switch ON.

Select the item below in the DATA LIST, and read the value displayed on the intelligent tester.

Air conditioning amplifier

DATA LIST DETAIL

Item	Measurement Item / Display (Range)	Normal Condition	Diagnostic Note
ROOM TEMP	Room temperature sensor / Min.: -6.5°C (20.3°F) Max.: 57.25°C (135.05°F)	Actual room temperature is displayed	Open circuit: -6.5°C (20.3°F) Short circuit: 57.25°C (135.05°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 ASSEMBLY

A: GO TO NEXT STEP.

INSPECT COOLER THERMISTOR (ROOM TEMPERATURE SENSOR)

Remove the room temperature sensor.

Measure the resistance of the sensor.

Standard resistance

TERMINALS RESISTANCE SPECIFICATION

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

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 Fig 1).

NG: REPLACE COOLER THERMISTOR (ROOM TEMPERATURE SENSOR)

Fig 1: Room Temperature Sensor Resistance Graph

OK: GO TO NEXT STEP.

CHECK WIRE HARNESS (ROOM TEMPERATURE SENSOR - AIR CONDITIONING AMPLIFIER)

Disconnect the E21 sensor connector.
Disconnect the E37 amplifier connector.

Fig 2: Disconnecting E21 & E37 Connectors
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Measure the resistance of the wire harness side connectors.

Standard resistance

TERMINALS RESISTANCE SPECIFICATION (CONNECTOR(S) DISCONNECTED)

Tester Connection	Specified Condition
E21-1 (ST+) - E37-29 (TR)	Below 1
E21-2 (ST-) - E37-34 (SG-1)	Below 1
E21-1 (ST+) - Body ground	1 M or higher
E21-2 (ST-) - Body ground	1 M or higher

NG: REPAIR OR REPLACE HARNESS AND CONNECTOR

OK: REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY