DTC P0712: Transmission Fluid Temperature Sensor "A" Circuit Low Input; DTC P0713: Transmission Fluid Temperature Sensor "A" Circuit High Input [11/2021 - ]: Description

WARNING: This page is about a different car, the 2024 Lexus IS 500, 2023 Lexus IS 500, and 2022 Lexus IS 500. However, it is still accessible from the selected car via links, so may be relevant.

The transmission fluid pressure control circuit's fluid temperature is detected using the Automatic Transmission Fluid (ATF) temperature sensor, which is built onto the valve body. A signal that is based on the fluid temperature is then sent to the TCM.

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The TCM applies voltage to the ATF temperature sensor through TCM terminal THO1 (OIL).

The sensor resistance changes with the ATF temperature. As the temperature becomes higher, the sensor resistance decreases.

One terminal of the sensor is grounded so that the sensor resistance decreases and the voltage decreases as the temperature becomes higher.

The TCM calculates the ATF temperature based on the voltage signal.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	MIL	Memory
P0712	Transmission Fluid Temperature Sensor "A" Circuit Low Input	1. Diagnosis Condition 2. Malfunction Status 3. Malfunction Time 4. Other The battery voltage is 8 V or more, the engine switch is on (IG) and the starter is off. ATF temperature sensor resistance is less than 79 Ω 0.5 seconds 1-trip detection logic	Short in ATF temperature sensor circuit Transmission wire (ATF temperature sensor) TCM	Comes on	DTC stored
P0713	Transmission Fluid Temperature Sensor "A" Circuit High Input	1. Diagnosis Condition 2. Malfunction Status 3. Malfunction Time 4. Other DTC Detection Condition 1 536 seconds or more after starting engine (Engine coolant temperature and intake air temperature at engine start are -29.375°C (-20.875°F)) or less ATF temperature sensor resistance is higher than 156 kΩ 0.5 seconds 1-trip detection logic DTC Detection Condition 2 10 seconds or more after starting engine (Engine coolant temperature and intake air temperature at engine start are more than -29.375°C (-20.875°F)) ATF temperature sensor resistance is higher than 156 kΩ 0.5 seconds 1-trip detection logic	Open in ATF temperature sensor circuit Transmission wire (ATF temperature sensor) TCM	Comes on	DTC stored

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

MIL

Memory

P0712

Transmission Fluid Temperature Sensor "A" Circuit Low Input

1. Diagnosis Condition 2. Malfunction Status 3. Malfunction Time 4. Other

The battery voltage is 8 V or more, the engine switch is on (IG) and the starter is off.
ATF temperature sensor resistance is less than 79 Ω
0.5 seconds
1-trip detection logic

Short in ATF temperature sensor circuit
Transmission wire (ATF temperature sensor)
TCM

Comes on

DTC stored

P0713

Transmission Fluid Temperature Sensor "A" Circuit High Input

1. Diagnosis Condition 2. Malfunction Status 3. Malfunction Time 4. Other
DTC Detection Condition 1

536 seconds or more after starting engine (Engine coolant temperature and intake air temperature at engine start are -29.375°C (-20.875°F)) or less
ATF temperature sensor resistance is higher than 156 kΩ
0.5 seconds
1-trip detection logic

DTC Detection Condition 2

10 seconds or more after starting engine (Engine coolant temperature and intake air temperature at engine start are more than -29.375°C (-20.875°F))
ATF temperature sensor resistance is higher than 156 kΩ
0.5 seconds
1-trip detection logic

Open in ATF temperature sensor circuit
Transmission wire (ATF temperature sensor)
TCM

Comes on

DTC stored