Lexus RX (RX 350L, RX450h) 2016-2024 Repair Manual: Pressure Control Solenoid "C" Actuator Stuck Off (P07957F)

Lexus RX (RX 350L, RX450h) 2016-2024 Repair Manual / Drivetrain / U881e (automatic Transmission / Transaxle) / Automatic Transaxle System / Pressure Control Solenoid "C" Actuator Stuck Off (P07957F)

DESCRIPTION

Based on signals from the transmission revolution sensors (NT, NC3 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 shift solenoid valves, transmission valve body assembly and automatic transaxle assembly (clutch, brake, gear, etc.).

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

ECM commanded gear

1st

2nd

3rd

4th

5th

6th

7th

8th
*: Neutral

Actual gear during SL3 stuck ON malfunction

3rd

3rd

3rd

3rd

7th

7th

7th

7th

Actual gear during SL3 stuck OFF malfunction

1st

2nd

N (1st)*

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

1. Diagnosis Condition, 2. Malfunction Status, 3. Malfunction Time, 4. Other

SL3 stuck ON malfunction:
  • Engine coolant temperature is 40°C (104°F) or higher, ATF temperature is -10°C (14°F) or higher, and the vehicle is being driven with the shift lever in D (no malfunctions are detected in the shift solenoid valves SL1, SL2, SL3, SL4, SL5 and S1, transmission revolution sensors (NT, NC3, NC), coolant temperature sensor, oil temperature sensor, knock control sensor, electronic throttle or CAN2)
  • One of the following occurs:
    1. When the ECM commands the transaxle to shift to 1st, 2nd or 4th gear, the actual gear changes to 3rd gear.
    2. When the ECM commands the transaxle to shift to 5th, 6th or 8th gear, the actual gear changes to 7th gear.
  • Malfunction status continues for 0.6 seconds or more
  • 2-trip detection logic
SL3 stuck OFF malfunction:
  • Engine coolant temperature is 40°C (104°F) or higher, ATF temperature is -10°C (14°F) or higher, and the vehicle is being driven with the shift lever in D (no malfunctions are detected in the shift solenoid valves SL1, SL2, SL3, SL4, SL5 and S1, transmission revolution sensors (NT, NC3, NC), coolant temperature sensor, oil temperature sensor, knock control sensor, electronic throttle or CAN2)
  • When the ECM commands the transaxle to shift to 3rd or 7th gear, the engine overruns (neutral status).
  • Malfunction status continues for 0.5 seconds or more
  • 2-trip detection logic
  • Shift solenoid valve S1
  • Shift solenoid valve SLT
  • Shift solenoid valve SL1
  • Shift solenoid valve SL2
  • Shift solenoid valve SL3
  • Shift solenoid valve SL4
  • Shift solenoid valve SL5
  • Transmission valve body assembly
  • Torque converter assembly
  • Automatic transaxle assembly (clutch, brake, gear, etc.)

Comes on

DTC stored

SAE Code:

P0796

MONITOR DESCRIPTION

The ECM commands gear shifts by turning the shift solenoid valves on and off. According to the input shaft revolution (speed), C3 clutch drum 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:

Shift solenoid valve SL3/OFF malfunction

Shift solenoid valve SL3/ON malfunction

Required sensors/Components

Shift solenoid valve SL3

Frequency of operation

Continuous

Duration

OFF malfunction (A): 0.6 sec.

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

OFF malfunction (D) and (E): Immediate

ON malfunction (A), (B), (C) and (D): 0.6 sec.

ON malfunction (E) and (F): Immediate

MIL operation

2 driving cycles

Sequence of operation

None

TYPICAL ENABLING CONDITIONS

All

The monitor will run whenever this DTC is not present.

(Not circuit malfunction)

P0717, P07BF, P07C0 (Turbine speed sensor circuit)

P07C1, P07C2, P2767 (Input speed sensor circuit)

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

P0335, P0337, P0338 (Crankshaft Position Sensor "A" circuit) (This condition applies only if using fail-safe)

P0748 (Shift solenoid valve SL1 circuit)

P0778 (Shift solenoid valve SL2 circuit)

P0798 (Shift solenoid valve SL3 circuit)

P2810 (Shift solenoid valve SL4 circuit)

P2819 (Shift solenoid valve SL5 circuit)

P0973, P0974 (Shift solenoid valve S1 circuit)

P0115, P0117, P0118 (ECT sensor circuit)

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

P0327, P0328, P032C, P032D, P0332, P0333, P033C, P033D (KCS sensor circuit)

P0120, P0121, P0122, P0123, P0220, P0222, P0223, P0604, P0606, P0607, P060A, P060B, P060D, P060E, P0657, P1607, P2102, P2103, P2111, P2112, P2118, P2119, P2135 ((ETCS) Electronic throttle control system)

U0100 (CAN communication system)

NSW switch

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

Duration time from shifting "N" to "D"

4 sec. or more

ATF temperature

-10°C (14°F) or more

Engine

Starting

Fail-safe does not active due to following malfunctions:

  

Shift solenoid valve SL1

Not OFF or ON malfunction (P0746)

Shift solenoid valve SL2

Not OFF or ON malfunction (P0776)

Shift solenoid valve SL3

Not OFF or ON malfunction (P0796)

Shift solenoid valve SL4

Not OFF or ON malfunction (P2808)

Shift solenoid valve SL5

Not OFF or ON malfunction (P2817)

Shift solenoid valve S1

Not OFF or ON malfunction (P0751, P0752)
OFF malfunction (A)

TCM selected gear

3rd

Vehicle speed

3 km/h (1.87 mph) or more

Throttle valve opening angle

3% or more at engine speed 1000 rpm

(conditions vary with engine speed)

Calculated load value

7.75% or more

ECT

40°C (104°F) or more

Spark advance from MAX. retard timing by KCS control

0 °CA or more
OFF malfunction (B)

TCM selected gear

3rd

Calculated load value

7.75% or more

Throttle valve opening angle

2% or more

Output speed

330 rpm or more

TCM indicated pressure value of SL1

1600 kPa (16.3 kgf/cm2, 232 psi) or more

TCM indicated pressure value of SL3

1600 kPa (16.3 kgf/cm2, 232 psi) or more

Turbine speed/Input speed (NT/NC3)

Less than 1.9 or more than 2.0
OFF malfunction (C)
*1: Duration (0.5 sec.)

TCM selected gear

7th

Calculated load value

7.75% or more

Throttle valve opening angle

2% or more

Turbine speed / Input speed (NT/NC3)

Less than 1.9 or more than 2.0

TCM indicated pressure value of SL2

1600 kPa (16.3 kgf/cm2, 232 psi) or more

TCM indicated pressure value of SL3

330 kPa (3.4 kgf/cm2, 48 psi) or more

Turbine speed - Output speed x 6th gear ratio (NT-NO x 6th gear ratio)

More than 50 rpm

Count up time*1 stops when following conditions met: (a) or (b)

  

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

1.064 or more and 1.233 or less

(when output speed less than 600 rpm)

(b) Turbine speed - Output speed (NT - NO) x 5th gear ratio

-50 rpm or more and 50 rpm or less

(when output speed 600 rpm or more)
OFF malfunction (D)

TCM selected gear

3rd
OFF malfunction (E)

TCM selected gear

7th
ON malfunction (A)

TCM selected gear

1st

Vehicle speed

3 km/h (1.87 mph) or more and less than 38 km/h (23.75 mph)

Engine speed - Turbine speed

150 rpm or more

Calculated load value

7.75% or more

ECT

40°C (104°F) or more

Spark advance from MAX. retard timing by KCS control

0 °CA or more

TCM indicated pressure value of SLT

Less than 320 kPa (3.3 kgf/cm2, 46 psi)
ON malfunction (B)

TCM selected gear

2nd

Vehicle speed

3 km/h (1.87 mph) or more

Throttle valve opening angle

3% or more at engine speed 1000 rpm

(conditions vary with engine speed)

Calculated load value

7.75% or more

ECT

40°C (104°F) or more

Spark advance from MAX. retard timing by KCS control

0 °CA or more

TCM indicated pressure value of SLT

Less than 320 kPa (3.3 kgf/cm2, 46 psi)
ON malfunction (C)

TCM selected gear

4th

Vehicle speed

3 km/h (1.87 mph) or more

Throttle valve opening angle

3% or more at engine speed 1000 rpm

(conditions vary with engine speed)

Calculated load value

7.75% or more

ECT

40°C (104°F) or more

Spark advance from MAX. retard timing by KCS control

0 °CA or more

TCM indicated pressure value of SLT

Less than 320 kPa (3.3 kgf/cm2, 46 psi)
ON malfunction (D)

TCM selected gear

5th

Vehicle speed

3 km/h (1.87 mph) or more

Throttle valve opening angle

3% or more at engine speed 1000 rpm

(conditions vary with engine speed)

Calculated load value

7.75% or more

ECT

40°C (104°F) or more

Spark advance from MAX. retard timing by KCS control

0 °CA or more
ON malfunction (E)

TCM selected gear

4th
ON malfunction (F)

TCM selected gear

8th

TYPICAL MALFUNCTION THRESHOLDS

OFF malfunction
  • When either conditions below is met: OFF malfunction (A), (B), (C), (D) or (E) OFF malfunction (A)

    When either condition below is met: (a) or (b)

    		  

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

    4.197 or more and 8.529 or less

    (When Output speed less than 130 rpm)

    (b) Turbine speed - Output speed x 1st gear ratio

    -50 rpm or more and 50 rpm or less

    (When Output speed 130 rpm or more)
    OFF malfunction (B)

    Turbine speed - Output speed x 3rd gear ratio (NT-NO x 3rd gear)

    400 rpm or more
    OFF malfunction (C)

    Turbine speed - Output speed x 7th gear ratio (NT-NO x 7th gear)

    400 rpm or more
    OFF malfunction (D) and (E)

    Shift solenoid valve SLT

    ON malfunction
ON malfunction
  • When either conditions below is met: OFF malfunction (A), (B), (C), (D) or (E) ON malfunction (A)

    When either condition below is met: (a) or (b)

    		  

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

    1.712 or more and 1.962 or less

    (When Output speed less than 400 rpm)

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

    -50 rpm or more and 50 rpm or less

    (When Output speed 400 rpm or more)
    ON malfunction (B)

    When either condition below is met: (a) or (b)

    		  

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

    1.712 or more and 1.962 or less

    (When Output speed less than 400 rpm)

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

    -50 rpm or more and 50 rpm or less

    (When Output speed 400 rpm or more)
    ON malfunction (C)

    When either condition below is met: (a) or (b)

    		  

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

    1.712 or more and 1.962 or less

    (When Output speed less than 400 rpm)

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

    -50 rpm or more and 50 rpm or less

    (When Output speed 400 rpm or more)
    ON malfunction (D)

    When either condition below is met: (a) or (b)

    		  

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

    0.701 or more and 0.825 or less

    (When Output speed less than 800 rpm)

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

    -50 rpm or more and 50 rpm or less

    (When Output speed 800 rpm or more)
    ON malfunction (E) and (F)

    Shift solenoid valve SLT

    ON malfunction

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 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

    HINT:

    [*1] : Normal judgment procedure.

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

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

CAUTION / NOTICE / HINT

NOTICE:

  • Perform the universal trip to clear permanent DTCs.

    Click here

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

    Click here

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, P07507E, P07757F, P27137F, P28077F and/or P28167F are output

A

Only DTC P07957F is output

B

DTC P07457F, P07507E, P07757F, P07957F, P27137F, P28077F, P28167F and other DTCs are output

C

HINT:

  • If any DTCs other than P07457F, P07507E, P07757F, P07957F, P27137F, P28077F and P28167F are output, perform troubleshooting for those DTCs first.
  • If a shift solenoid valve is stuck ON or OFF, DTCs for several shift solenoid valves including the malfunctioning shift solenoid valve will be stored.
B

GO TO STEP 3

C

GO TO DTC CHART

A

2.

CLEAR DTC AND PERFORM STALL SPEED TEST

(a) Clear the DTCs.

Click here

HINT:

Write down the currently output DTCs before clearing them.

Powertrain > Transmission > Clear DTCs

(b) Perform the stall speed test.

Click here

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 SHIFT SOLENOID VALVE SL1, SL2, SL3, SL4 AND SL5

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

Click here

*a

Component without harness connected

(Shift Solenoid Valve SL1, SL2, SL3, SL4 and SL5)

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

Shift solenoid valve SL1 connector terminal 1 - terminal 2

20°C (68°F)

5.0 to 5.6 Ω

Shift solenoid valve SL2 connector terminal 1 - terminal 2

20°C (68°F)

5.0 to 5.6 Ω

Shift solenoid valve SL3 connector terminal 1 - terminal 2

20°C (68°F)

5.0 to 5.6 Ω

Shift solenoid valve SL4 connector terminal 1 - terminal 2

20°C (68°F)

5.0 to 5.6 Ω

Shift solenoid valve SL5 connector terminal 1 - terminal 2

20°C (68°F)

5.0 to 5.6 Ω

(c) Connect a positive (+) lead from the battery to terminal 1 and a negative (-) lead with a 21 W bulb 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 SHIFT SOLENOID VALVE SL1, SL2, SL3, SL4 OR SL5

OK

4.

INSPECT SHIFT SOLENOID VALVE S1

(a) Remove the shift solenoid valve S1.

Click here

*1

Shift Solenoid Valve S1

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

Shift solenoid valve S1 connector terminal - Shift solenoid valve S1 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 SHIFT SOLENOID VALVE S1

OK

5.

INSPECT SHIFT SOLENOID VALVE SLT

(a) Remove the shift solenoid valve SLT.

Click here

*a

Component without harness connected

(Shift Solenoid Valve SLT)

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

Shift solenoid valve SLT connector terminal 1 - terminal 2

20°C (68°F)

5.0 to 5.6 Ω

(c) Connect a positive (+) lead from the battery to terminal 1 and a negative (-) lead with a 21 W bulb 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 SHIFT SOLENOID VALVE SLT

OK

6.

INSPECT TRANSMISSION VALVE BODY ASSEMBLY

(a) Inspect the transmission valve body assembly.

Click here

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

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

NEXT

PERFORM A/T CODE REGISTRATION

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