A340F Automatic Transmission System

A340F AUTOMATIC TRANSMISSION: AUTOMATIC TRANSMISSION SYSTEM: P0712,P0713: Transmission Fluid Temperature Sensor "A" Circuit Low Input


DESCRIPTION

The ATF (Automatic Transmission Fluid) temperature sensor converts the fluid temperature into a resistance value which is input into the ECM. The No. 2 ATF temperature sensor is on the transmission, just before the oil cooler inlet pipeline.

HINT
The ATF temperature is liable to increase under conditions such as towing, climbing hills and in traffic.

The table below shows the symptoms and recovery conditions for when the sensor is normal and when the sensor has a short circuit.





HINT
*1: When the ATF temperature is normal, the transmission locks up in 4th gear with the shift lever in D and in 3rd gear with the shift lever in 3rd.





MONITOR DESCRIPTION

The Automatic Transmission Fluid (ATF) temperature sensor converts the ATF temperature to an electrical resistance value. Based on the resistance, the ECM determines the ATF temperature, and detects any open or short malfunctions in the ATF temperature circuit. If the resistance of the ATF temperature is less than 79 Ohms or more than 156 kOhms, the ECM interprets this as a fault in the ATF temperature sensor or its wiring. The ECM stores a DTC.

WIRING DIAGRAM





INSPECTION PROCEDURE

NOTICE:
Perform the universal trip to clear permanent DTCs DTC Check / Clear.

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.

1. Warm up the engine.

2. Turn the ignition switch off.

3. Connect the Techstream to the DLC3.

4. Turn the ignition switch to ON.

5. Turn the Techstream on.

6. Enter the following menus: Powertrain / Engine and ECT / Data List.

7. According to the display on the Techstream, read the Data List.

Engine and ECT





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

When DTC P0713 is output 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.





If a circuit related to the ATF temperature sensor becomes open, P0713 is immediately stored (in 0.5 seconds).

PROCEDURE

1. INSPECT NO. 2 ATF TEMPERATURE SENSOR

(a) Disconnect the No. 2 ATF temperature sensor connector.





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

Standard Resistance:





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

Standard Resistance:





Text in Illustration





NG -- REPLACE NO. 2 ATF TEMPERATURE SENSOR Removal
OK -- Continue to next step.

2. CHECK HARNESS AND CONNECTOR (NO. 2 ATF TEMPERATURE SENSOR - ECM)





(a) Disconnect the No. 2 ATF temperature sensor connector.

(b) Disconnect the ECM connector.

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

Standard Resistance:





Text in Illustration





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE ECM Removal