Last Modified: 08-21-2023 6.11:8.1.0 Doc ID: RM100000001K344
Model Year Start: 2020 Model: Avalon Prod Date Range: [08/2019 -           ]
Title: UA80E (AUTOMATIC TRANSMISSION / TRANSAXLE): AUTOMATIC TRANSAXLE SYSTEM: P07957F; Pressure Control Solenoid "C" Actuator Stuck Off; 2020 - 2022 MY Avalon [08/2019 -        ]

DTC

P07957F

Pressure Control Solenoid "C" Actuator Stuck Off

DESCRIPTION

Based on signals from the transmission revolution sensors (NT and NC), the actual gear is detected.

The ECM compares the actual gear with the shift schedule in the ECM memory to detect mechanical malfunctions of the solenoid valves, transmission valve body assembly and automatic transaxle assembly (clutch, brake, gear, etc.).

Actual gear when solenoid (SL3) valve malfunction occurs (without fail-safe control):

ECM commanded gear

1st

2nd

3rd

4th

5th

6th

7th

8th
*: Neutral

Actual gear during SL3 stuck ON malfunction

3rd

3rd

3rd

3rd

3rd to 5th

7th

7th

7th

Actual gear during SL3 stuck OFF malfunction

1st

2nd

N*

4th

5th

6th

N*

8th

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

MIL

Memory

Note

P07957F

Pressure Control Solenoid "C" Actuator Stuck Off

All of the following conditions are met (2-trip detection logic):

  • Engine coolant temperature is 40°C (104°F) or higher.
  • ATF temperature is -10°C (14°F) or higher.
  • The vehicle is being driven with the shift lever in D.
  • No malfunctions are detected in the solenoid (SL1, SL2, SL3, SL4, SL5, SL6, SL, SLU and SLT) valves, transmission revolution sensors (NT and NC), coolant temperature sensor, oil temperature sensor, knock sensor, crankshaft position sensor circuits, electronic throttle or CAN communication system.
  • Any of the following conditions are met:
    • When the ECM commands the transaxle to shift to 1st, 2nd, 4th or 5th gear, the actual gear changes to 3rd gear for 0.8 seconds or more.
    • When the ECM commands the transaxle to shift to 6th or 8th gear, the actual gear changes to 7th gear for 0.8 seconds or more.
    • When the ECM commands the transaxle to shift to 3rd or 7th gear, the engine overruns (neutral status) for 0.5 seconds or more.
  • Solenoid (SL1) valve
  • Solenoid (SL2) valve
  • Solenoid (SL3) valve
  • Solenoid (SL4) valve
  • Solenoid (SL5) valve
  • Solenoid (SL6) valve
  • Solenoid (SL) valve
  • Solenoid (SLU) valve
  • Solenoid (SLT) valve
  • Transmission valve body assembly
  • Torque converter assembly
  • Automatic transaxle assembly (clutch, brake, gear, etc.)

Comes on

DTC stored

SAE Code:

P0796

DTC Detection Condition Patterns:

 

Vehicle Condition

Pattern 1

Pattern 2

Pattern 3

Pattern 4

Diagnostic Condition

Engine coolant temperature is 40°C (104°F) or higher.

○

○

○

○

ATF temperature is -10°C (14°F) or higher.

○

○

○

○

The vehicle is being driven with the shift lever in D.

○

○

○

○

No malfunctions are detected in the solenoid (SL1, SL2, SL3, SL4, SL5, SL6, SL, SLU and SLT) valves, transmission revolution sensors (NT and NC), coolant temperature sensor, oil temperature sensor, knock sensor, crankshaft position sensor circuits, electronic throttle or CAN communication system.

○

○

○

○

Malfunction Condition

When the ECM commands the transaxle to shift to 1st gear, the actual gear changes to 3rd gear.

○

-

-

-

When the ECM commands the transaxle to shift to 2nd gear, the actual gear changes to 3rd gear.

-

○

-

-

When the ECM commands the transaxle to shift to 4th gear, the actual gear changes to 3rd gear.

-

-

○

-

When the ECM commands the transaxle to shift to 5th gear, the actual gear changes to 3rd to 5th gear.

-

-

-

○

Duration

0.8 seconds or more

0.8 seconds or more

0.8 seconds or more

0.8 seconds or more

Detection Logic

2-trip detection logic

2-trip detection logic

2-trip detection logic

2-trip detection logic

DTC Detection Condition Patterns:

 

Vehicle Condition

Pattern 5

Pattern 6

Pattern 7

Pattern 8

Diagnostic Condition

Engine coolant temperature is 40°C (104°F) or higher.

○

○

○

○

ATF temperature is -10°C (14°F) or higher.

○

○

○

○

The vehicle is being driven with the shift lever in D.

○

○

○

○

No malfunctions are detected in the solenoid (SL1, SL2, SL3, SL4, SL5, SL6, SL, SLU and SLT) valves, transmission revolution sensors (NT and NC), coolant temperature sensor, oil temperature sensor, knock sensor, crankshaft position sensor circuits, electronic throttle or CAN communication system.

○

○

○

○

Malfunction Condition

When the ECM commands the transaxle to shift to 6th gear, the actual gear changes to 7th gear.

○

-

-

-

When the ECM commands the transaxle to shift to 8th gear, the actual gear changes to 7th gear.

-

○

-

-

When the ECM commands the transaxle to shift to 3rd gear, the engine overruns (neutral status).

-

-

○

-

When the ECM commands the transaxle to shift to 7th gear, the engine overruns (neutral status).

-

-

-

○

Duration

0.8 seconds or more

0.8 seconds or more

0.5 seconds or more

0.5 seconds or more

Detection Logic

2-trip detection logic

2-trip detection logic

2-trip detection logic

2-trip detection logic

HINT:

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

MONITOR DESCRIPTION

The ECM commands gear shifts by turning the solenoid valves on and off. According to the input shaft revolution (speed) and output shaft revolution (speed), the ECM detects the actual gear (1st, 2nd, 3rd, 4th, 5th, 6th, 7th or 8th gear). When the gear commanded by the ECM and the actual gear are not the same, the ECM illuminates the MIL and stores a DTC.

MONITOR STRATEGY

Related DTCs

P0796:

Solenoid (SL3) valve/OFF malfunction

Solenoid (SL3) valve/ON malfunction

Required sensors/components

Solenoid (SL3) valve

Frequency of operation

Continuous

Duration

OFF malfunction (A) and (B): 0.5 sec.

OFF malfunction (C): -

ON malfunction (A), (B), (C), (D) and (E): 0.8 sec.

ON malfunction (F): -

MIL operation

2 driving cycles

Sequence of operation

None

TYPICAL ENABLING CONDITIONS

All

The monitor will run whenever the following DTCs are not stored

P0717, P07BF, P07C0 (Turbine speed sensor circuit)

P0793, P07C5, P07C6 (Intermediate shaft speed sensor circuit)

P0962, P0963 (Solenoid (SL1) valve circuit)

P0966, P0967 (Solenoid (SL2) valve circuit)

P0970, P0971 (Solenoid (SL3) valve circuit)

P2814, P2815 (Solenoid (SL4) valve circuit)

P281D, P281E (Solenoid (SL5) valve circuit)

P08C1, P08C2 (Solenoid (SL6) valve circuit)

P2769, P2770 (Solenoid (SL) valve circuit)

P2763, P2764 (Solenoid (SLU) valve circuit)

P2720, P2721 (Solenoid (SLT) valve circuit)

P0117, P0118 (ECT sensor circuit)

P0335, P0337, P0338 (Crankshaft position sensor circuit)

P0712, P0713 (ATF temperature sensor circuit (TFT sensor))

P0327, P0328, P0332, P0333 (KCS sensor circuit)

P0121, P0122, P0123, P0222, P0223, P0604, P0606, P060A, P060B, P060D, P060E, P061E, P0657, P0658, P2102, P2103, P2111, P2112, P2119, P2135 ((ETCS) Electronic throttle control system)

U0100 (CAN communication system)

Shift position

"D", "not R" and "not N"

Elapsed time since shift lever moved from "N" to "D"

4 sec. or more

ATF temperature

-10°C (14°F) or more

Engine

Starting

Fail-safe function does not operate due to the following malfunctions:

-

Solenoid (SL1) valve

OFF or ON malfunction (P0746)

Solenoid (SL2) valve

OFF or ON malfunction (P0776)

Solenoid (SL3) valve

OFF or ON malfunction (P0796)

Solenoid (SL4) valve

OFF or ON malfunction (P2808)

Solenoid (SL5) valve

OFF or ON malfunction (P2817)

Solenoid (SL6) valve

OFF or ON malfunction (P08BB)

Solenoid (SLT) valve

OFF malfunction (P2714)

Solenoid (SLU) valve

ON malfunction (P2757)

Solenoid (SL) valve

ON malfunction (P0741)

All shift solenoids

Not being stopped

Neutral command flag

Not met

OFF malfunction (A)

ECM selected gear

7th

Neutral state detected when 3rd gear commanded

-

Vehicle stop check

Fixed

OFF malfunction (B)

ECM selected gear

3rd

Neutral state detected when 7th gear commanded

-

Vehicle stop check

Fixed

ON malfunction (A)

ECM selected gear

1st

Vehicle speed

2 km/h (1.2 mph) or more and less than 38 km/h (23.6 mph)

Throttle valve opening angle

5% or more at engine speed 2000 rpm

(conditions vary with engine speed)

Calculated load value

-

- When A/C off

16% or more

- When A/C on

19% or more

ECT

40°C (104°F) or more

Spark advance from MAX. retard timing by KCS control

0 °CA or more

Calculated input torque

0 N*m (0 kgf*cm, 0 ft.*lbf) or more

ON malfunction (B)

ECM selected gear

2nd

Vehicle speed

2 km/h (1.2 mph) or more

Throttle valve opening angle

5% or more at engine speed 2000 rpm

(conditions vary with engine speed)

Calculated load value

-

- When A/C off

16% or more

- When A/C on

19% or more

ECT

40°C (104°F) or more

Spark advance from MAX. retard timing by KCS control

0 °CA or more

Calculated input torque

0 N*m (0 kgf*cm, 0 ft.*lbf) or more

ON malfunction (C)

ECM selected gear

4th

Vehicle speed

2 km/h (1.2 mph) or more

Throttle valve opening angle

5% or more at engine speed 2000 rpm

(conditions vary with engine speed)

Calculated load value

-

- When A/C off

16% or more

- When A/C on

19% or more

ECT

40°C (104°F) or more

Spark advance from MAX. retard timing by KCS control

0 °CA or more

Calculated input torque

0 N*m (0 kgf*cm, 0 ft.*lbf) or more

ON malfunction (D)

ECM selected gear

6th

Vehicle speed

2 km/h (1.2 mph) or more

Throttle valve opening angle

5% or more at engine speed 2000 rpm

(conditions vary with engine speed)

Calculated load value

-

- When A/C off

16% or more

- When A/C on

19% or more

ECT

40°C (104°F) or more

Spark advance from MAX. retard timing by KCS control

0 °CA or more

Calculated input torque

0 N*m (0 kgf*cm, 0 ft.*lbf) or more

ON malfunction (E)

ECM selected gear

8th

Vehicle speed

2 km/h (1.2 mph) or more

Throttle valve opening angle

5% or more at engine speed 2000 rpm

(conditions vary with engine speed)

Calculated load value

-

- When A/C off

16% or more

- When A/C on

19% or more

ECT

40°C (104°F) or more

Spark advance from MAX. retard timing by KCS control

0 °CA or more

Calculated input torque

0 N*m (0 kgf*cm, 0 ft.*lbf) or more

Neutral state flag:

Turbine speed - output speed x (ECM selected gear ratio)

1000 rpm or more

Neutral state detection:

Neutral state flag

ON
  • Any of the following conditions are met: Condition (a) or (b)

    • Condition (a)

      ECM selected gear

      3rd

      Output speed x 5th gear ratio

      Less than 6500 rpm

      Condition (b)

      ECM selected gear

      7th

      Turbine speed - output speed x 3rd gear ratio

      More than 50 rpm

      Output speed x 5th gear ratio

      Less than 6500 rpm

Vehicle stop check:

Vehicle speed

Less than 0 km/h (0 mph)

Neutral command flag:

Engine speed

7200 rpm or more

Turbine speed

7200 rpm or more
  • Any of the following conditions are met: Condition (a) or (b)
    • Condition (a)

      ECM selected gear

      6th or 7th or 8th

      Output speed x 5th gear ratio

      7200 rpm or more

      Condition (b)

      ECM selected gear

      4th or 5th

      Output speed x 3rd gear ratio

      7200 rpm or more

TYPICAL MALFUNCTION THRESHOLDS

OFF malfunction

  • Any of the following conditions are met: OFF malfunction (A), (B) or (C)

    OFF malfunction (A) and (B)

    Neutral state flag

    ON

    OFF malfunction (C)

    Solenoid (SLT) valve

    ON malfunction
    • Any of the following conditions are met: Condition (a) or (b)

      Condition (a)

      ECM selected gear

      3rd

      3rd gear pass detection

      Not fixed after transition to latest gear

      Condition (b)

      ECM selected gear

      7th

      7th gear pass detection

      Not fixed after transition to latest gear

ON malfunction

  • Any of the following conditions are met: ON malfunction (A), (B), (C), (D), (E) or (F)

    ON malfunction (A), (B) and (C)

    Any of the following conditions are met

    (a) or (b)

    (a) Turbine speed/Output speed (NT/NO)

    1.910 or more and 2.189 or less

    (When output speed less than 350 rpm)

    (b) Turbine speed - Output speed x 3rd gear ratio

    -50 rpm or more and 50 rpm or less

    (When output speed 350 rpm or more)

    ON malfunction (D) and (E)

    Any of the following conditions are met

    (a) or (b)

    (a) Turbine speed/Output speed (NT/NO)

    0.737 or more and 0.867 or less

    (When output speed less than 750 rpm)

    (b) Turbine speed - Output speed x 7th gear ratio

    -50 rpm or more and 50 rpm or less

    (When output speed 750 rpm or more)

    ON malfunction (F)

    Solenoid (SLT) valve

    ON malfunction
    • Any of the following conditions are met: Condition (a), (b) or (c)

      Condition (a)

      ECM selected gear

      4th

      4th gear pass detection

      Not fixed after transition to latest gear

      Condition (b)

      ECM selected gear

      5th

      5th gear pass detection

      Not fixed after transition to latest gear

      Condition (c)

      ECM selected gear

      8th

      8th gear pass detection

      Not fixed after transition to latest gear

Neutral state flag:

Turbine speed - Output speed x (ECM selected gear ratio)

1000 rpm or more

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 2019 - 2022 MY Avalon [04/2018 -        ]; UA80E (AUTOMATIC TRANSMISSION / TRANSAXLE): AUTOMATIC TRANSAXLE SYSTEM: DTC CHECK / CLEAR

  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 2 minutes or more.
  5. Turn the engine switch on (IG) and turn the Techstream on.
  6. Start the engine.
  7. Perform the D Position Shift Test inspection in Road Test. [*1]

    Click here 2019 - 2022 MY Avalon [04/2018 -        ]; UA80E (AUTOMATIC TRANSMISSION / TRANSAXLE): AUTOMATIC TRANSAXLE SYSTEM: ROAD TEST

    HINT:

    [*1] : Normal judgment procedure.

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

  8. Stop the vehicle.
  9. Enter the following menus: Powertrain / Transmission / Utility / All Readiness.
  10. Input the DTC: P07957F.
  11. 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.

CAUTION / NOTICE / HINT

NOTICE:

  • Perform the universal trip to clear permanent DTCs.

    Click here 2019 - 2022 MY Avalon [04/2018 -        ]; UA80E (AUTOMATIC TRANSMISSION / TRANSAXLE): AUTOMATIC TRANSAXLE SYSTEM: DTC CHECK / CLEAR

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

    Click here 2019 - 2021 MY Avalon [04/2018 - 08/2021]; UA80E (AUTOMATIC TRANSMISSION / TRANSAXLE): AUTOMATIC TRANSAXLE SYSTEM: PRECAUTION 2022 MY Avalon [08/2021 -        ]; UA80E (AUTOMATIC TRANSMISSION / TRANSAXLE): AUTOMATIC TRANSAXLE SYSTEM: PRECAUTION

PROCEDURE

1.

CHECK DTC OUTPUT (IN ADDITION TO DTC P07957F)

(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.

Powertrain > Transmission > Trouble Codes

(e) Read the DTCs using the Techstream.

Result

Proceed to

DTC P07957F and DTC P07457F, P07407E, P07757F, P08BA7F, P27137F, P28077F and/or P28167F are output

A

Only DTC P07957F is output

B

DTCs other than P07457F, P07407E, P07757F, P07957F, P08BA7F, P27137F, P28077F and P28167F are also output

C

HINT:

  • If any DTCs other than P07457F, P07407E, P07757F, P07957F, P08BA7F, P27137F, P28077F and P28167F are output, perform troubleshooting for those DTCs first.
  • If a solenoid valve is stuck ON or OFF, DTCs for several solenoid valves including the malfunctioning solenoid valve will be stored.
B

GO TO STEP 3

C

GO TO DTC CHART 2020 MY Avalon [08/2019 - 08/2020]; UA80E (AUTOMATIC TRANSMISSION / TRANSAXLE): AUTOMATIC TRANSAXLE SYSTEM: DIAGNOSTIC TROUBLE CODE CHART 2021 - 2022 MY Avalon [08/2020 -        ]; UA80E (AUTOMATIC TRANSMISSION / TRANSAXLE): AUTOMATIC TRANSAXLE SYSTEM: DIAGNOSTIC TROUBLE CODE CHART

A

2.

CLEAR DTC AND PERFORM STALL SPEED TEST

(a) Clear the DTCs.

Powertrain > Transmission > Clear DTCs

HINT:

Write down the currently output DTCs before clearing them.

(b) Perform the stall speed test.

Click here 2019 - 2022 MY Avalon [04/2018 -        ]; UA80E (AUTOMATIC TRANSMISSION / TRANSAXLE): AUTOMATIC TRANSAXLE SYSTEM: MECHANICAL SYSTEM TESTS

Test Condition

Proceed to

Stall speed test can be performed

A

Stall speed test cannot be performed

B
B

GO TO STEP 5

A

3.

INSPECT SOLENOID (SL1), (SL2), (SL3), (SL4), (SL5) AND (SL6) VALVE

(a) Remove the solenoid (SL1), (SL2), (SL3), (SL4), (SL5) and (SL6) valves.

Click here 2019 - 2022 MY Avalon [04/2018 -        ]; UA80E (AUTOMATIC TRANSMISSION / TRANSAXLE): VALVE BODY ASSEMBLY: DISASSEMBLY

*a

Component without harness connected

(Solenoid (SL1), (SL2), (SL3), (SL4), (SL5) and (SL6) Valves)

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

Solenoid (SL1) valve connector terminal 1 - terminal 2

20°C (68°F)

5.0 to 5.6 Ω

Solenoid (SL2) valve connector terminal 1 - terminal 2

20°C (68°F)

5.0 to 5.6 Ω

Solenoid (SL3) valve connector terminal 1 - terminal 2

20°C (68°F)

5.0 to 5.6 Ω

Solenoid (SL4) valve connector terminal 1 - terminal 2

20°C (68°F)

5.0 to 5.6 Ω

Solenoid (SL5) valve connector terminal 1 - terminal 2

20°C (68°F)

5.0 to 5.6 Ω

Solenoid (SL6) valve connector terminal 1 - terminal 2

20°C (68°F)

5.0 to 5.6 Ω

(c) Connect a positive (+) lead from the battery with a 21 W bulb to terminal 1 and a negative (-) lead to terminal 2 of the solenoid valve connector. Check that the valve moves and makes an operating sound.

OK:

Valve moves and makes an operating sound.

NG

REPLACE SOLENOID (SL1), (SL2), (SL3), (SL4), (SL5) OR (SL6) VALVE

OK

4.

INSPECT SOLENOID (SL) VALVE

(a) Remove the solenoid (SL) valve.

Click here 2019 - 2022 MY Avalon [04/2018 -        ]; UA80E (AUTOMATIC TRANSMISSION / TRANSAXLE): VALVE BODY ASSEMBLY: DISASSEMBLY

*1

Solenoid (SL) Valve

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

Solenoid (SL) valve connector terminal - Solenoid (SL) valve body

20°C (68°F)

11 to 15 Ω

(c) Connect a positive (+) lead from the battery to the terminal of the solenoid valve connector, and a negative (-) lead to the solenoid body. Check that the valve moves and makes an operating sound.

OK:

Valve moves and makes an operating sound.

NG

REPLACE SOLENOID (SL) VALVE

OK

5.

INSPECT SOLENOID (SLT) VALVE

(a) Remove the solenoid (SLT) valve.

Click here 2019 - 2022 MY Avalon [04/2018 -        ]; UA80E (AUTOMATIC TRANSMISSION / TRANSAXLE): VALVE BODY ASSEMBLY: DISASSEMBLY

*a

Component without harness connected

(Solenoid (SLT) Valve)

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

Solenoid (SLT) valve connector terminal 1 - terminal 2

20°C (68°F)

5.0 to 5.6 Ω

(c) Connect a positive (+) lead from the battery with a 21 W bulb to terminal 1 and a negative (-) lead to terminal 2 of the solenoid valve connector. Check that the valve moves and makes an operating sound.

OK:

Valve moves and makes an operating sound.

NG

REPLACE SOLENOID (SLT) VALVE

OK

6.

INSPECT TRANSMISSION VALVE BODY ASSEMBLY

(a) Inspect the transmission valve body assembly.

Click here 2019 - 2022 MY Avalon [04/2018 -        ]; UA80E (AUTOMATIC TRANSMISSION / TRANSAXLE): VALVE BODY ASSEMBLY: REMOVAL

OK:

There is no foreign matter on each valve and they operate smoothly.

NG

REPAIR OR REPLACE TRANSMISSION VALVE BODY ASSEMBLY

OK

7.

INSPECT TORQUE CONVERTER ASSEMBLY

(a) Inspect the torque converter assembly.

Click here 2019 - 2022 MY Avalon [04/2018 -        ]; UA80E (AUTOMATIC TRANSMISSION / TRANSAXLE): TORQUE CONVERTER AND DRIVE PLATE: INSPECTION

OK:

The torque converter assembly is normal.

NG

REPAIR OR REPLACE TORQUE CONVERTER ASSEMBLY

OK

8.

REPAIR OR REPLACE AUTOMATIC TRANSAXLE ASSEMBLY

(a) Repair or replace the automatic transaxle assembly.

Click here 2020 - 2022 MY Avalon [08/2019 -        ]; UA80E (AUTOMATIC TRANSMISSION / TRANSAXLE): AUTOMATIC TRANSAXLE ASSEMBLY: COMPONENTS

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