Dtc 11 Room Temperature Sensor Circuit


DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

INSPECT COOLER THERMISTOR

CHECK AIR CONDITIONING AMPLIFIER ASSEMBLY

CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER - COOLER THERMISTOR)

DTC 11 Room Temperature Sensor Circuit


DESCRIPTION

The cooler thermistor is installed in the instrument panel to detect the room temperature and control the heater and air conditioning AUTO function. The resistance of the cooler thermistor changes in accordance with the 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 cooler thermistor and reads voltage changes as the resistance of the cooler thermistor changes.

DTC Code
DTC Detection Condition
Trouble Area
11
An open or short in the room temperature sensor circuit.
  1. Cooler thermistor
  2. Air conditioning amplifier assembly
  3. Harness or connector

WIRING DIAGRAM


Toyota Fortuner. Ggn50, 60 Kun51, 61 Tgn51 Lan50.Air Conditioning.Air Conditioning System (For Automatic Air Conditioning System). Dtc 11 Room Temperature Sensor Circuit


INSPECTION PROCEDURE

1.INSPECT COOLER THERMISTOR


    Toyota Fortuner. Ggn50, 60 Kun51, 61 Tgn51 Lan50.Air Conditioning.Air Conditioning System (For Automatic Air Conditioning System). Dtc 11 Room Temperature Sensor Circuit

  1. Remove the cooler thermistor (Toyota Fortuner RM000001G9F01EX.html).

  1. 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
    Text in Illustration
    *a
    		Resistance (kΩ)
    *b
    		Temperature
    NOTICE:
    1. Even slightly touching the cooler thermistor may change the resistance value. Be sure to hold the connector of the cooler thermistor.
    2. When measuring the resistance, the cooler thermistor temperature must be the same as the ambient temperature.
    HINT:
    As the temperature increases, the resistance decreases (Refer to the graph).


NG
REPLACE COOLER THERMISTOR (Toyota Fortuner RM000001G9F01EX.html)
OK


2.CHECK AIR CONDITIONING AMPLIFIER ASSEMBLY


    Toyota Fortuner. Ggn50, 60 Kun51, 61 Tgn51 Lan50.Air Conditioning.Air Conditioning System (For Automatic Air Conditioning System). Dtc 11 Room Temperature Sensor Circuit

  1. Remove the air conditioning amplifier assembly with its connectors still connected (Toyota Fortuner RM000001K3A018X.html).

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

    Standard Voltage:
    Tester Connection
    		Condition
    		Specified Condition
    A37-18 (TR) - A37-13 (SG-3)
    1. Ignition switch ON
    2. Cabin temperature 25°C (77°F)
    		1.8 to 2.2 V
    1. Ignition switch ON
    2. Cabin temperature 40°C (104°F)
    		1.2 to 1.6 V
    Text in Illustration
    *a
    		Component with harness connected
    (Air Conditioning Amplifier Assembly)
    HINT:
    As the temperature increases, the voltage decreases.
    Result
    Result
    		Proceed to
    OK (When troubleshooting according to problem symptoms table.)
    		A
    OK (When troubleshooting according to DTC.)
    		B
    NG
    		C


B
REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY (Toyota Fortuner RM000001K3A018X.html)

C
Go to step 3
A

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE (Toyota Fortuner RM0000045E300YX.html)

3.CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER - COOLER THERMISTOR)

  1. Disconnect the A37 air conditioning amplifier assembly connector.

  1. Disconnect the A17 cooler thermistor connector.

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    A37-18 (TR) - A17-2
    		Always
    		Below 1 Ω
    A37-13 (SG-3) - A17-1
    A37-18 (TR) - Body ground
    		Always
    		10 kΩ or higher
    A37-13 (SG-3) - Body ground


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY (Toyota Fortuner RM000001K3A018X.html)