Home › Drivetrain › Automatic Transmission/Transaxle › AB60F AUTOMATIC TRANSMISSION / TRANSAXLE: AUTOMATIC TRANSMISSION SYSTEM
Last Modified: 11-27-2007 1.6 C
Service Category: Drivetrain Section: Automatic Transmission/Transaxle
Model Year: 2008 Model: LX570 Doc ID: RM000000W8507HX
Title: AB60F AUTOMATIC TRANSMISSION / TRANSAXLE: AUTOMATIC TRANSMISSION SYSTEM: DESCRIPTION (2008 LX570)

DTC

P0710

Transmission Fluid Temperature Sensor "A" Circuit

DTC

P0712

Transmission Fluid Temperature Sensor "A" Circuit Low Input

DTC

P0713

Transmission Fluid Temperature Sensor "A" Circuit High Input

DESCRIPTION

The Automatic Transmission Fluid (ATF) temperature sensor converts the fluid temperature into a resistance value which is input into the ECM.

The ECM applies voltage to the temperature sensor through the ECM terminal THO1.

The sensor resistance changes with the transmission fluid 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 goes down as the temperature becomes higher.

The ECM calculates the fluid temperature based on the voltage signal.



DTC Code

DTC Detection Condition

Trouble Area

P0710

(a) and (b) are detected momentarily within 0.5 sec. when neither P0712 nor P0713 are stored (1-trip detection logic).

(a) The No. 1 ATF temperature sensor resistance is below 79 Ω.

(b) The No. 1 ATF temperature sensor resistance is higher than 156 kΩ.

HINT:

Within 0.5 sec., the malfunction switches from (a) to (b) or from (b) to (a).
  • Open or short in No. 1 ATF temperature sensor circuit
  • No. 1 transmission wire (No. 1 ATF temperature sensor)
  • ECM

P0712

The No. 1 ATF temperature sensor resistance is below 79 Ω for 0.5 sec. or more (1-trip detection logic).
  • Short in No. 1 ATF temperature sensor circuit
  • No. 1 transmission wire (No. 1 ATF temperature sensor)
  • ECM

P0713

When 15 min. or more have elapsed after the engine is started, the No. 1 ATF temperature sensor resistance is higher than 156 kΩ for 0.5 sec. or more (1-trip detection logic).
  • Open in No. 1 ATF temperature sensor circuit
  • No. 1 transmission wire (No. 1 ATF temperature sensor)
  • ECM

MONITOR DESCRIPTION

These DTCs indicate an open or short in the Automatic Transmission Fluid (ATF) temperature sensor circuit. The ATF temperature sensor converts the ATF temperature to an electrical resistance value. Based on the resistance, the ECM determines the ATF temperature, and the ECM detects an open or short in the ATF temperature circuit. If the resistance value of the ATF temperature is below 79 Ω*1 or higher than 156 kΩ*2, the ECM interprets this as a fault in the ATF sensor or wiring. The ECM will turn on the MIL and store the DTC.

HINT:

  • The ATF temperature can be checked on the Techstream display.
  • *1: 150°C (302°F) or higher is indicated regardless of the actual ATF temperature.
  • *2: -40°C (-40°F) is indicated regardless of the actual ATF temperature.

MONITOR STRATEGY

Related DTCs

P0710: ATF temperature sensor/Range check (Chattering)

P0712: ATF temperature sensor/Range check (Low resistance)

P0713: ATF temperature sensor/Range check (High resistance)

Required sensors/Components

ATF temperature sensor (TFT sensor)

Frequency of operation

Continuous

Duration

0.5 sec.

MIL operation

Immediately

Sequence of operation

None

TYPICAL ENABLING CONDITIONS

All

The monitor will run whenever the following DTCs are not stored

None

P0710, P0712: Range Check (Chattering, Low Resistance)

The typical enabling condition is not available

-

P0713: Range Check (High Resistance)

Time after engine start

15 min. or more

TYPICAL MALFUNCTION THRESHOLDS

P0710: Range Check (Chattering)

ATF temperature sensor resistance

Below 79 Ω or higher than 156 kΩ

P0712: Range Check (Low Resistance)

ATF temperature sensor resistance

Below 79 Ω

P0713: Range Check (High Resistance)

ATF temperature sensor resistance

Higher than 156 kΩ

COMPONENT OPERATING RANGE

ATF temperature sensor resistance

79 Ω to 156 kΩ

WIRING DIAGRAM

INSPECTION PROCEDURE

1. DATA LIST

HINT:

Using the Techstream to read the Data List allows the values or states of switches, sensors, actuators and other items to be read without removing any parts. This non-intrusive inspection can be very useful because intermittent conditions or signals may be discovered before parts or wiring is disturbed. Reading the Data List information early in troubleshooting is one way to save diagnostic time.

NOTICE:

In the table below, the values listed under "Normal Condition" are reference values. Do not depend solely on these reference values when deciding whether a part is faulty or not.

(a) Warm up the engine.

(b) Turn the engine switch off.

(c) Connect the Techstream to the DLC3.

(d) Turn the engine switch on (IG).

(e) Turn the Techstream on.

(f) Enter the following menus: Powertrain / Engine and ECT / Data List.

(g) According to the display on the Techstream, read the Data List.

Engine and ECT

Tester Display

Measurement Item/Range

Normal Condition

Diagnostic Note

A/T Oil Temperature 1

No. 1 ATF temperature sensor value/

Min.: -40°C (-40°F)

Max.: 215°C (419°F)
  • After stall test: Approximately 80°C (176°F)
  • With engine cold: Equal to ambient temperature

If the value is -40°C (-40°F) or 215°C (419°F), the No. 1 ATF temperature sensor circuit is open or shorted.

HINT:

When DTC P0712 is stored and the Techstream output is 150°C (302°F) or higher, there is a short circuit.

When DTC P0713 is stored and the Techstream output is -40°C (-40°F), there is an open circuit.

Check the temperature displayed on the Techstream in order to check if a malfunction exists.

Temperature Displayed

Malfunction

-40°C (-40°F)

Open circuit

150°C (302°F) or higher

Short circuit

If a circuit related to the ATF temperature sensor becomes open, P0713 is immediately stored (in 0.5 seconds). When P0713 is stored, P0711 cannot be stored. It is not necessary to inspect the circuit when P0711 is stored.

PROCEDURE

1.

INSPECT NO. 1 TRANSMISSION WIRE (NO. 1 ATF TEMPERATURE SENSOR)

(a) Disconnect the C39 No. 1 transmission wire connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

9 (OT+) - 1 (OT-)

Always

79 Ω to 156 kΩ

9 (OT+) - Body ground

Always

10 kΩ or higher

1 (OT-) - Body ground

Always

10 kΩ or higher

HINT:

If the resistance is out of the specified range at one of the ATF temperatures shown in the table below, the driveability of the vehicle may decrease.

Resistance (Reference):

ATF Temperature

Specified Condition

10°C (50°F)

5 to 8 kΩ

25°C (77°F)

2.5 to 4.5 kΩ

110°C (230°F)

0.22 to 0.28 kΩ
OK

2.

CHECK HARNESS AND CONNECTOR (NO. 1 TRANSMISSION WIRE - ECM)

(a) Disconnect the C53 ECM connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

C53-122 (THO1) - C53-98 (ETHA)

Always

79 Ω to 156 kΩ

C53-122 (THO1) - Body ground

Always

10 kΩ or higher

C53-98 (ETHA) - Body ground

Always

10 kΩ or higher
OK