Dtc 12 Ambient Temperature Sensor Circuit

Vehicle Interior. Hilux. Tgn26, 36 Kun25, 26, 35, 36 Ggn25
Heating Air Conditioning. Hilux. Tgn26, 36 Kun25, 26, 35, 36 Ggn25

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

CHECK ACCESSORY METER ASSEMBLY

CHECK HARNESS AND CONNECTOR (ACCESSORY METER - AIR CONDITIONING AMPLIFIER)

INSPECT THERMISTOR ASSEMBLY

CHECK HARNESS AND CONNECTOR (ACCESSORY METER - THERMISTOR)

DTC 12 Ambient Temperature Sensor Circuit


DESCRIPTION

The thermistor assembly connected to the accessory meter detects fluctuations in the ambient temperature. This information is used for controlling the interior temperature. The accessory meter detects the resistance of the thermistor assembly and sends this information to the air conditioning amplifier assembly.

DTC Code
DTC Detection Condition
Trouble Area
12
An open or short in ambient temperature sensor circuit
  1. Thermistor assembly
  2. Accessory meter assembly
  3. Air conditioning amplifier assembly
  4. Harness or connector

WIRING DIAGRAM


Hilux. Tgn26, 36 Kun25, 26, 35, 36 Ggn25.Heating Air Conditioning.Air Conditioning System (For Automatic Air Conditioning System). Dtc 12 Ambient Temperature Sensor Circuit


INSPECTION PROCEDURE

NOTICE:
Check that the accessory meter assembly illuminates normally before performing the following inspection procedure.
1.CHECK ACCESSORY METER ASSEMBLY

  1. Check the difference between the ambient temperature value displayed on the accessory meter assembly and the actual ambient temperature.

    OK:
    The ambient temperature displayed on the accessory meter assembly and the actual ambient temperature are almost the same.
    HINT:
    The temperature displayed on the accessory meter assembly and the actual temperature detected by the thermistor assembly may differ when the ambient temperature changes significantly (for example, when the vehicle is entering/exiting tunnels, or the vehicle speed or wind direction changes).


NG
Go to step 3
OK


2.CHECK HARNESS AND CONNECTOR (ACCESSORY METER - AIR CONDITIONING AMPLIFIER)

  1. Disconnect the G32 accessory meter assembly connector.

  1. Disconnect the G94 air conditioning amplifier assembly connector.

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    G32-9 (DATA) - G94-18 (TAMO)
    		Always
    		Below 1 Ω
    G32-9 (DATA) - Body ground
    		Always
    		10 kΩ or higher
    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 (HILUX_TGN26 RM000001K3A024X.html)

C
REPAIR OR REPLACE HARNESS OR CONNECTOR
A

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE (HILUX_TGN26 RM0000045E301VX.html)

3.INSPECT THERMISTOR ASSEMBLY


    Hilux. Tgn26, 36 Kun25, 26, 35, 36 Ggn25.Heating Air Conditioning.Air Conditioning System (For Automatic Air Conditioning System). Dtc 12 Ambient Temperature Sensor Circuit

  1. Remove the thermistor assembly (HILUX_TGN26 RM000002VYK02GX.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 thermistor assembly may change the resistance value. Be sure to hold the connector of the thermistor assembly.
    2. When measuring the resistance, the thermistor assembly temperature must be the same as the ambient temperature.
    HINT:
    As the temperature increases, the resistance decreases (Refer to the graph).


NG
REPLACE THERMISTOR ASSEMBLY (HILUX_TGN26 RM000002VYK02GX.html)
OK


4.CHECK HARNESS AND CONNECTOR (ACCESSORY METER - THERMISTOR)

  1. Disconnect the G32 accessory meter assembly connector.

  1. Disconnect the A22 thermistor assembly connector.

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    G32-3 (TH+) - A22-2
    		Always
    		Below 1 Ω
    G32-2 (SG) - A22-1
    G32-3 (TH+) - Body ground
    		Always
    		10 kΩ or higher
    G32-2 (SG) - Body ground


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

REPLACE ACCESSORY METER ASSEMBLY (HILUX_TGN26 RM000004QVA008X.html)