P0712

U340E AUTOMATIC TRANSMISSION / TRANSAXLE: AUTOMATIC TRANSAXLE SYSTEM (for Hatchback): 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 to the ECM.

The sensor resistance changes with the transmission fluid temperature. As the temperature rises, the sensor resistance decreases. The ECM applies a voltage to the temperature sensor through ECM terminal THO1, and the ECM calculates the fluid temperature based on the voltage signal.

HINT
* The ATF temperature is likely to increase under conditions such as towing, climbing hills and in heavy traffic.
* When the ATF temperature sensor 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 ATF temperature sensor converts the ATF temperature to an electrical resistance value. Based on the resistance, the ECM determines the ATF temperature and detects opens or shorts in the ATF temperature circuit. If the resistance value of the ATF temperature is less than 79 Ohms*1 or more than 156 kOhms*2, the ECM interprets this as a fault in the ATF sensor or wiring. The ECM turns on the MIL and stores the DTC.

*1: 150°C (302°F) or more is indicated regardless of the actual ATF temperature.

*2: -40°C (-40°F) is indicated regardless of the actual ATF temperature.

HINT
The ATF temperature can be checked on the Techstream display.

MONITOR STRATEGY





TYPICAL ENABLING CONDITIONS

P0712: Range check (Low resistance)





P0713: Range check (High resistance)

One of the following conditions is met: Condition (A) or (B).

Condition (A)





Condition (B)





TYPICAL MALFUNCTION THRESHOLDS

P0712: Range check (Low resistance)





P0713: Range check (High resistance)





COMPONENT OPERATING RANGE





WIRING DIAGRAM





INSPECTION PROCEDURE

NOTICE:
Perform the universal trip to clear permanent DTCs Reading and Clearing Diagnostic Trouble Codes.

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 ignition switch off.

(c) Connect the Techstream to the DLC3.

(d) Turn the ignition switch to ON.

(e) Turn the Techstream on.

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

(g) In accordance with the display on the Techstream, read the Data List.





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

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

Measure the resistance between terminal THO1 and the body ground.





HINT
If a circuit related to the ATF (Automatic Transmission Fluid) temperature sensor becomes open, P0713 is immediately set (within 0.5 seconds).

PROCEDURE

1. INSPECT TRANSMISSION WIRE (ATF TEMPERATURE SENSOR)





(a) Disconnect the transmission wire connector from the transaxle.

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

Standard Resistance:





Text in Illustration





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

Standard Resistance:





NG -- REPLACE TRANSMISSION WIRE Removal (from 07/2011)
OK -- Continue to next step.

2. CHECK HARNESS AND CONNECTOR (TRANSMISSION WIRE - ECM)





(a) Connect the transmission wire connector to the transaxle.

(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 (from 07/2011)