Toyota Avalon (XX50) 2019-2022 Service & Repair Manual: Transmission Fluid Temperature Sensor "A" Circuit Range/Performance (P071000)

DESCRIPTION

The ATF temperature sensor converts the automatic transaxle fluid (ATF) temperature into a resistance value for use by the ECM.

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

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

One terminal of the sensor is grounded so that the sensor resistance and voltage decrease as the temperature rises.

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

HINT:

This DTC is stored when either of the above detection patterns is met.

MONITOR DESCRIPTION

This DTC indicates that there is a problem with the output signals from the ATF temperature sensor and that the sensor itself is defective. The ATF temperature sensor converts the ATF temperature into an electrical resistance value. Based on the resistance, the ECM determines the ATF temperature and detects an open or short in the ATF temperature circuit or a malfunction of the ATF temperature sensor.

After driving the vehicle for a certain period of time, the ATF temperature should increase. If the ATF temperature is below 20°C (68°F) after driving the vehicle for a certain period, the ECM interprets this as a malfunction, illuminates the MIL and stores this DTC.

If the ATF temperature is 110°C (230°F) or higher and the engine coolant temperature takes 10 seconds or more to reach 60°C (140°F) after a cold start, the ECM also interprets this as a malfunction, illuminates the MIL and stores this DTC.

MONITOR STRATEGY

TYPICAL ENABLING CONDITIONS

HINT:

*1: Following conditions are met

*2: Time after engine start is cleared when following condition met

*3: Driving distance is cleared when following condition met

*4: IAT is measured when either of following conditions met

TYPICAL MALFUNCTION THRESHOLDS

One of the following conditions is met: Condition (A), (B), (C), (D) or (E)

COMPONENT OPERATING RANGE

CONFIRMATION DRIVING PATTERN

CAUTION:

When performing the confirmation driving pattern, obey all speed limits and traffic laws.

HINT:

• After repairs have been completed, clear the DTCs and then check that the vehicle has returned to normal by performing the following All Readiness check procedure.
• When clearing the permanent DTCs, refer to the Clear Permanent DTC procedure.

  Click here

1. Connect the Techstream to the DLC3.
2. Turn the engine switch on (IG) and turn the Techstream on.
3. Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).
4. Turn the engine switch off and wait for at least 5 hours. [*1]
5. Turn the engine switch on (IG) and turn the Techstream on. [*2]
6. Start the engine and perform both of the following [*3]:
   • Drive the vehicle 20 km (12 mile) or more over a period of 9 minutes and 5 seconds or more.
   • Wait until 40 minutes or more have elapsed since the engine started.

     HINT:

     [*1] to [*3] : Normal judgment procedure.

     The normal judgment procedure is used to complete DTC judgment and also used when clearing permanent DTCs.

7. Stop the vehicle.
8. Enter the following menus: Powertrain / Transmission / Utility / All Readiness.
9. Input the DTC: P071000.
10. Check the DTC judgment result.

    Techstream Display	Description
    NORMAL	DTC judgment completed System normal
    ABNORMAL	DTC judgment completed System abnormal
    INCOMPLETE	DTC judgment not completed Perform driving pattern after confirming DTC enabling conditions
    N/A	Unable to perform DTC judgment Number of DTCs which do not fulfill DTC preconditions has reached ECU memory limit

    HINT:

    • If the judgment result shows NORMAL, the system is normal.
    • If the judgment result shows ABNORMAL, the system has a malfunction.
    • If the judgment result shows INCOMPLETE or N/A, perform the normal judgment procedure again.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

• Perform the universal trip to clear permanent DTCs.

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• Perform registration and/or initialization when parts related to the automatic transaxle are replaced.

  Click here

• If DTCs P071000, P261029 and/or P261093 are output simultaneously, using the Techstream, check if the ATF temperature is as specified under the "Normal Condition" column of the Data List. If the ATF temperature is as specified under the "Normal Condition" column, perform troubleshooting for DTC P261029.

  Click here

DATA LIST

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.

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.

(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 / Transmission / Data List / A/T Oil Temperature No.1.

(g) Read the Data List according to the display on the Techstream.

HINT:

• If DTC P071011 is output and the Techstream indicates 150°C (302°F) or higher, there is a short in the circuit.
• If DTC P071015 is output and the Techstream indicates -40°C (-40°F), the circuit is open.

  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, P071015 will be stored in approximately 0.5 seconds. If DTC P071015 is stored, DTC P071000 cannot be detected. It is not necessary to inspect the circuit when P071000 is output.

PROCEDURE

(a) Connect the Techstream to the DLC3.

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

(c) Turn the Techstream on.

(d) Enter the following menus: Powertrain / Transmission / Trouble Codes.

(e) Read the DTCs using the Techstream.

HINT:

If any DTCs other than DTC P071000 are output, perform troubleshooting for those DTCs first.

B

GO TO DTC CHART (DTC P071015)

C

GO TO DTC CHART

A

(a) Check the automatic transaxle fluid level.

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OK:

Automatic transaxle fluid level is correct.

NG

ADJUST AUTOMATIC TRANSAXLE FLUID LEVEL

OK

(a) Disconnect the C56 ECM 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 the ATF temperature shown in the table below, the driveability of the vehicle may decrease.

NG

GO TO STEP 5

OK

(a) Replace the ECM.

Click here

NEXT

PERFORM REGISTRATION

(a) Disconnect the C52 transmission wire connector.

(b) Disconnect the C56 ECM connector.

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

Standard Resistance:

OK

REPLACE TRANSMISSION WIRE (ATF TEMPERATURE SENSOR)

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR (TRANSMISSION WIRE - ECM)