Air Conditioning. Dtc B1411/11 Room Temperature Sensor Circuit

Heater & Air Conditioning System. Lexus Gs430, Gs300. Uzs190 Grs190

Air Conditioning. Lexus Gs430, Gs300. Uzs190 Grs190

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

READ VALUE OF INTELLIGENT TESTER

INSPECT ROOM TEMPERATURE SENSOR

CHECK WIRE HARNESS (ROOM TEMPERATURE SENSOR - A/C AMPLIFIER)

DTC B1411/11 Room Temperature Sensor Circuit

DESCRIPTION

The room temperature sensor is installed in the instrument panel to detect the room temperature and control the air conditioner "AUTO" mode. The resistance of the room temperature sensor changes in accordance with the room temperature. As the temperature decreases, the resistance increases. As the temperature increases, the resistance decreases.
The A/C amplifier applies voltage (5 V) to the room temperature sensor and reads voltage changes as the resistance of the room temperature sensor changes. This sensor also sends the appropriate signals to the A/C amplifier. The room temperature sensor is integrated with the room humidity sensor.

DTC No.	DTC Detection Condition	Trouble Area
B1411/11	Open or short in room temperature sensor circuit	Room temperature sensor Harness and connector between room temperature sensor and A/C amplifier A/C amplifier

WIRING DIAGRAM

Lexus Gs430, Gs300. Uzs190 Grs190.Air Conditioning.Air Conditioning System.
Dtc
B1411/11 Room Temperature Sensor Circuit

INSPECTION PROCEDURE

1.READ VALUE OF INTELLIGENT TESTER

Connect the intelligent tester to the DLC3.

Turn the engine switch on (IG) and push the intelligent tester main switch on.

Select the item below in the Data List, and read the display on the intelligent tester.

A/C amplifier:
Item	Measurement Item / Display (Range)	Normal Condition	Diagnostic Note
Room Temperature Sensor (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 in circuit: -6.5°C (20.3°F) Short in circuit: 57.25°C (135.05°F)

OK:: The display is as specified in the normal condition.

Result:
NG	A
OK (Checking from the PROBLEM SYMPTOMS TABLE)	B
OK (Checking from the DTC)	C

PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE

REPLACE AIR CONDITIONING AMPLIFIER

A

2.INSPECT ROOM TEMPERATURE SENSOR

Remove the room temperature sensor.

Measure the resistance of the sensor.

Standard resistance:

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

NOTICE:

Even slightly touching the sensor 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).

REPLACE ROOM TEMPERATURE SENSOR

OK

3.CHECK WIRE HARNESS (ROOM TEMPERATURE SENSOR - A/C AMPLIFIER)

Disconnect the L33 room temperature sensor connector.

Disconnect the L52 A/C amplifier connector.

Measure the resistance of the wire harness side connectors.

Standard resistance:

Tester Connection	Condition	Specified Condition
L33-1 (+) - L52-16 (TR)	Always	Below 1 Ω
L33-2 (-) - L52-19 (SG-1)	Always	Below 1 Ω
L52-16 (TR) - Body ground	Always	10 kΩ or higher
L52-19 (SG-1) - Body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS AND CONNECTOR

REPLACE AIR CONDITIONING AMPLIFIER