Dtc P0751 Shift Solenoid A Performance (Shift Solenoid Valve S1)

Drivetrain. Land Cruiser. Urj200, 202 Grj200 Vdj200
Ab60F Automatic Transmission Transaxle. Land Cruiser. Urj200, 202 Grj200 Vdj200

DESCRIPTION

MONITOR DESCRIPTION

INSPECTION PROCEDURE

CHECK DTC OUTPUT (IN ADDITION TO DTC P0751)

PERFORM ACTIVE TEST USING INTELLIGENT TESTER (SHIFT SOLENOID VALVE SLT)

INSPECT SHIFT SOLENOID VALVE S1

INSPECT TRANSMISSION VALVE BODY ASSEMBLY

DTC P0751 Shift Solenoid "A" Performance (Shift Solenoid Valve S1)


DESCRIPTION

The ECM uses signals from the output shaft speed sensor and input speed sensor to detect the actual gear position (1st, 2nd, 3rd, 4th, 5th or 6th gear).
Then the ECM compares the actual gear with the shift schedule in the ECM memory to detect mechanical problems with the shift solenoid valves, valve body or automatic transmission (clutch, brake or gear, etc.).

DTC Code
DTC Detection Condition
Trouble Area
P0751
A shift solenoid valve S1 stuck ON malfunction*1:
The ECM determines there is a malfunction when the following conditions are both met (2 trip detection logic*3, 1 trip detection logic*4).
(a) When the ECM directs the transmission to switch to 1st gear, the actual gear is shifted to 2nd.
(b) When the ECM directs the transmission to switch to 5th gear, the actual gear is also shifted to 5th.
  1. Shift solenoid valve S1 remains open
  2. Valve body is blocked
  3. Automatic transmission (clutch, brake or gear, etc.)
P0751
A shift solenoid valve S1 stuck OFF malfunction*2:
The ECM determines there is a malfunction when conditions (a) and (b), or (a) and (c) are met (2 trip detection logic*3, 1 trip detection logic*4).
(a) When the ECM directs the transmission to switch to 2nd gear, the actual gear is shifted to 1st.
(b) When the ECM directs the transmission to switch to 5th gear, the actual gear is also shifted to 5th.
(c) When the ECM directs the transmission to switch to 6th gear, the engine overruns (clutch slips).
  1. Shift solenoid valve S1 remains closed
  2. Shift solenoid valve SLT remains open or closed
  3. Valve body is blocked
  4. No. 2 brake malfunction (Driving is difficult.)
  5. Automatic transmission (clutch, brake or gear, etc.)
HINT:
  1. Gear positions in the event of a solenoid valve mechanical problem:

    ECM gear shift command
    		1st
    		2nd
    		3rd
    		4th
    		5th
    		6th
    *1: Actual gear position under S1 stuck ON malfunction
    		2nd
    		2nd
    		3rd
    		4th
    		5th
    		6th
    *2: Actual gear position under S1 stuck OFF malfunction
    		1st
    		1st
    		3rd
    		4th
    		5th
    		N*
    N*: Neutral
  2. Gear position during fail-safe operation:
    If any malfunction is detected, the ECM changes into the fail-safe mode to shift into the gear positions as shown in the table below.

    Gear position under normal conditions
    		1st
    		2nd
    		3rd
    		4th
    		5th
    		6th
    *1: Actual gear position under fail-safe mode when S1 stuck ON malfunction
    		2nd
    		2nd
    		3rd
    		4th
    		5th
    		6th
    *2: Actual gear position under fail-safe mode when S1 stuck OFF malfunction
    		1st*
    		1st*
    		3rd
    		3rd
    		3rd
    		3rd
    1st*: Under engine braking, downshifting to 1st or 2nd gear is prohibited.
  3. *3: w/ OBD
  4. *4: w/o OBD

MONITOR DESCRIPTION

This DTC indicates "stuck ON malfunction" or "stuck OFF malfunction" of the shift solenoid valve S1.
The ECM commands gear shifts by turning the shift solenoid valves "ON/OFF". When the gear position commanded by the ECM and the actual gear position are not the same, the ECM illuminates the MIL and stores the DTC.

INSPECTION PROCEDURE


ACTIVE TEST
HINT:
Using the intelligent tester to perform Active Tests allows relays, VSVs, actuators and other items to be operated without removing any parts. This non-intrusive functional inspection can be very useful because intermittent operation may be discovered before parts or wiring is disturbed. Performing Active Tests early in troubleshooting is one way to save diagnostic time. Data List information can be displayed while performing Active Tests.

  1. Warm up the engine.

  2. Turn the ignition switch off.

  3. Connect the intelligent tester to the DLC3.

  4. Turn the ignition switch to ON.

  5. Turn the intelligent tester on.

  6. Enter the following menus: Powertrain / ECT / Active Test.

  7. According to the display on the tester, perform the Active Test.

    HINT:
    While driving, the shift position can be forcibly changed with the intelligent tester.
    Comparing the shift position commanded by the Active Test with the actual shift position enables you to confirm the problem (Click here).

    ECT
    Tester Display
    		Test Part
    		Control Range
    		Diagnostic Note
    Control the Shift Position
    		Operate shift solenoid valve and set each shift position
    1. Press "→" button: Shift up
    1. Press "←" button: Shift down
    		It is possible to check the operation of the shift solenoid valves.
    [Vehicle Condition]
    The vehicle speed is 50 km/h (31 mph) or less.
    HINT:
    1. This test can be conducted when the vehicle speed is 50 km/h (31 mph) or less.
    2. The 4th to 5th and 5th to 6th up-shifts must be performed with the accelerator pedal released.
    3. The 6th to 5th and 5th to 4th down-shifts must be performed with the accelerator pedal released.
    4. Do not operate the accelerator pedal for at least 2 seconds after shifting and do not shift successively.
    5. The shift position commanded by the ECM is shown in the Data List display on the tester.
    6. The shift solenoid valve S1 turns ON/OFF normally when the shift lever is in D.

      ECM gear shift command
      		1st
      		2nd
      		3rd
      		4th
      		5th
      		6th
      Shift solenoid valve S1
      		OFF
      		ON
      		ON
      		ON
      		ON
      		ON
1.CHECK DTC OUTPUT (IN ADDITION TO DTC P0751)

  1. Connect the intelligent tester to the DLC3.

  1. Turn the ignition switch to ON.

  1. Turn the intelligent tester on.

  1. Enter the following menus: Powertrain / ECT / Trouble Codes.

  1. Read the DTCs using the tester.

    Result
    Result
    		Proceed to
    Only P0751 is output
    		A
    P0751 and other DTCs are output
    		B
    HINT:
    If any other codes besides P0751 are output, perform troubleshooting for those DTCs first.


B
GO TO DTC CHART (Click here)
A


2.PERFORM ACTIVE TEST USING INTELLIGENT TESTER (SHIFT SOLENOID VALVE SLT)
NOTICE:
  1. Perform the test at the normal operating ATF temperature: 50 to 80°C (122 to 176°F).
  2. Be careful to prevent SST hose from interfering with the exhaust pipe.
  3. Perform the test with the A/C turned off.
HINT:
Using the intelligent tester to perform Active Tests allows relays, VSVs, actuators and other items to be operated without removing any parts. This non-intrusive functional inspection can be very useful because intermittent operation may be discovered before parts or wiring is disturbed. Performing Active Tests early in troubleshooting is one way to save diagnostic time. Data List information can be displayed while performing Active Tests.


    Land Cruiser. Urj200, 202 Grj200 Vdj200.Ab60F Automatic Transmission Transaxle.Automatic Transmission System (For 1Ur-Fe). Dtc P0751 Shift Solenoid A Performance (Shift Solenoid Valve S1)

  1. Remove the test plug on the transmission case center right side and connect SST.

SST
09992-00095(09992-00231,09992-00271)

  1. Connect the intelligent tester to the DLC3.

  1. Start the engine and warm it up.

  1. Measure the line pressure with SST.

  1. Turn the intelligent tester on.

  1. Enter the following menus: Powertrain / ECT / Active Test.

  1. According to the display on the tester, perform the Active Test.

  1. Measure the line pressure.

    ECT
    Tester Display
    		Test Part
    		Control Range
    		Diagnostic Note
    Activate the Solenoid (SLT)*
    		Operate shift solenoid valve SLT and raise line pressure
    		ON or OFF
    HINT:
    1. OFF: Line pressure up (when Active Test "Activate the Solenoid (SLT)" is performed, ECM commands shift solenoid valve SLT to turn OFF)
    2. ON: No action (normal operation)
    		[Vehicle Condition]
    1. The vehicle is stopped.
    2. The engine is idling.
    HINT:
    *: Activate the Solenoid (SLT) in the Active Test is performed to check the line pressure changes by connecting SST to the automatic transmission, which is used in the Hydraulic Test (Click here) as well. Note that the pressure values in the Active Test and hydraulic test are different.
    OK:
    The line pressure changes as specified when performing the Active Test.


NG
REPLACE SHIFT SOLENOID VALVE SLT (Click here)
OK


3.INSPECT SHIFT SOLENOID VALVE S1


    Land Cruiser. Urj200, 202 Grj200 Vdj200.Ab60F Automatic Transmission Transaxle.Automatic Transmission System (For 1Ur-Fe). Dtc P0751 Shift Solenoid A Performance (Shift Solenoid Valve S1)

  1. Remove the shift solenoid valve S1.

  1. 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

  1. Apply 12 V battery voltage to the shift solenoid valve and check that the valve moves and makes an operating noise.

    OK:
    Measurement Condition
    		Specified Condition
    1. Battery positive (+) → Shift solenoid valve S1 connector
    2. Battery negative (-) → Shift solenoid valve S1 body
    		Valve moves and makes an operating noise


NG
REPLACE SHIFT SOLENOID VALVE S1 (Click here)
OK


4.INSPECT TRANSMISSION VALVE BODY ASSEMBLY

  1. Check the transmission valve body assembly (Click here).

    OK:
    There are no foreign objects on any valve.


NG
REPAIR OR REPLACE TRANSMISSION VALVE BODY ASSEMBLY (Click here)
OK

REPAIR OR REPLACE AUTOMATIC TRANSMISSION ASSEMBLY (Click here)