DTC B1411/11 Room Temperature Sensor Circuit

DESCRIPTION

The front room temperature sensor for the front seat is installed in the instrument panel to detect the room temperature and control the heater and air conditioner "auto" mode. The resistance of the room temperature sensor changes in accordance with the front room temperature. As the temperature decreases, the resistance increases. As the temperature increases, the resistance decreases.

The air conditioning amplifier assembly applies voltage (5 V) to the front room temperature sensor and reads voltage changes as the resistance of the front room temperature sensor changes. This sensor also sends the appropriate signals to the air conditioning amplifier assembly.

DTC Code	DTC Detection Condition	Trouble Area
B1411/11	An open or short in the front room temperature sensor circuit.	Front room temperature sensor Harness or connector between room temperature sensor and air conditioning amplifier assembly Air conditioning amplifier assembly

WIRING DIAGRAM

Dtc B1411/11 Room Temperature Sensor Circuit. HEATING / AIR CONDITIONING. Land Cruiser URJ200 URJ202 GRJ200 VDJ200

INSPECTION PROCEDURE

1.READ VALUE USING INTELLIGENT TESTER (FRONT ROOM TEMPERATURE SENSOR)

Use the Data List to check if the front room temperature sensor is functioning properly.

Air Conditioner
Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
Room Temperature Sensor	Front room temperature sensor / Min.: -6.5°C (20.3°F) Max.: 57.25°C (135.05°F)	Actual room temperature for front seat displayed	Open in the circuit: -6.5°C (20.3°F). Short in the circuit: 57.25°C (135.05°F).

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

Go to step 2

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY ()

2.INSPECT ROOM TEMPERATURE SENSOR

Dtc B1411/11 Room Temperature Sensor Circuit. HEATING / AIR CONDITIONING. Land Cruiser URJ200 URJ202 GRJ200 VDJ200

Remove the front room temperature sensor ().

Measure the resistance according to the value(s) in the table below.

Standard Resistance:

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

OK

3.CHECK HARNESS AND CONNECTOR (FRONT ROOM TEMPERATURE SENSOR - AIR CONDITIONING AMPLIFIER)

w/ Rear Heater

Disconnect the E32 sensor connector.

Disconnect the E35 amplifier connector.

Measure the resistance according to the value(s) in the table below.

Standard Resistance:
Tester Connection Condition Specified Condition
E32-1 (+) - E35-9 (TR) Always Below 1 Ω
E32-2 (-) - E35-32 (SG-1)
E35-9 (TR) - Body ground Always 10 kΩ or higher
E35-32 (SG-1) - Body ground

w/o Rear Heater

Disconnect the E32 sensor connector.

Disconnect the E81 amplifier connector.

Measure the resistance according to the value(s) in the table below.

Standard Resistance:
Tester Connection Condition Specified Condition
E32-1 (+) - E81-29 (TR) Always Below 1 Ω
E32-2 (-) - E81-34 (SG-1)
E81-29 (TR) - Body ground Always 10 kΩ or higher
E81-34 (SG-1) - Body ground

REPAIR OR REPLACE HARNESS OR CONNECTOR

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY ()

Tester Connection	Condition	Specified Condition
E32-1 (+) - E35-9 (TR)	Always	Below 1 Ω
E32-2 (-) - E35-32 (SG-1)
E35-9 (TR) - Body ground	Always	10 kΩ or higher
E35-32 (SG-1) - Body ground

Tester Connection	Condition	Specified Condition
E32-1 (+) - E81-29 (TR)	Always	Below 1 Ω
E32-2 (-) - E81-34 (SG-1)
E81-29 (TR) - Body ground	Always	10 kΩ or higher
E81-34 (SG-1) - Body ground