DTC B1412: Ambient Temperature Sensor Circuit [12/2019 - 11/2023]: Procedure

1. Read the Data List according to the display on the GTS.

   Body Electrical > Air Conditioner > Data List 

   Tester Display	Measurement Item	Range	Normal Condition	Diagnostic Note
   Ambient Temp Sensor	Ambient temp. sensor (thermistor assembly)	Min.: -23.30°C (-9.94°F) Max.: 65.95°C (150.71°F)	Actual ambient temperature displayed	Ambient temp. sensor (thermistor assembly) circuit malfunction When open circuit: -23.30°C (-9.94°F) When short circuit: 65.95°C (150.71°F)

   Body Electrical > Air Conditioner > Data List 

   Tester Display
   Ambient Temp Sensor

   OK

   The display is as specified in the normal condition column.

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY. Refer to  REMOVAL [12/2019 - 10/2022]  , or refer to  REMOVAL [10/2022 - 11/2023] 

Result: 

NG 

See step  2

Refer to INSPECTION [12/2019 - ]

Result

Result: 

NG 

REPLACE AMBIENT TEMP. SENSOR (THERMISTOR ASSEMBLY). Refer to  REMOVAL [12/2019 - 09/2020]  , or refer to  REMOVAL [09/2020 - 10/2021]  , or refer to  REMOVAL [10/2021 - 11/2023] 

Result: 

OK 

See step  3

1. Disconnect the H63 air conditioning amplifier assembly connector.
2. Disconnect the A23 ambient temp. sensor (thermistor assembly) connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   H63-1 (TAM) - A23-2	Always	Below 1 Ω
   H63-14 (SG-2) - A23-1	Always	Below 1 Ω
   H63-1 (TAM) or A23-2 - Other terminals and body ground	Always	10 kΩ or higher
   H63-14 (SG-2) or A23-1 - Other terminals and body ground	Always	10 kΩ or higher

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY. Refer to  REMOVAL [12/2019 - 10/2022]  , or refer to  REMOVAL [10/2022 - 11/2023] 

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR