Dtc P0781 1-2 Shift (1-2 Shift Valve)

DESCRIPTION

MONITOR DESCRIPTION

INSPECTION PROCEDURE

CHECK DTC OUTPUT (IN ADDITION TO DTC P0781)

PERFORM ACTIVE TEST USING INTELLIGENT TESTER (RUNNING TEST)

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

CLEAR DTC AND PERFORM RUNNING TEST

DESCRIPTION

1. 
   The 1-2 shift valve performs shifting to 1st gear and other gears.
   
   

   DTC Code	DTC Detection Condition	Trouble Area
   P0781	Gear required by the TCM does not match the actual gear when driving (2-trip detection logic).	Valve body is blocked up or stuck (1-2 shift valve) Shift solenoid valve SLT remains open or closed Automatic transmission (clutch, brake, gear, etc.)

MONITOR DESCRIPTION

INSPECTION PROCEDURE

1. Connect the intelligent tester to the DLC3.
   

2. Turn the ignition switch to ON.
   

3. Turn the intelligent tester on.
   

4. Enter the following menus: Powertrain / ECT / DTC.
   

5. Read the DTCs using the tester.
   

   Result

   Result	Proceed to
   Only P0781 is output	A
   P0781 and other DTCs are output	B

   HINT:

   If any other codes besides P0781 are output, perform troubleshooting for those DTCs first.

CAUTION:

This test should always be performed with at least 2 people.

NOTICE:

1. Perform the test while the ATF temperature is between 50 and 80°C (122 and 176°F).
   
2. 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.

1. Connect the intelligent tester to the DLC3.
   

2. Clear the DTC (HILUX_TGN26 RM000000W770U5X.html).
   

3. Warm up the engine.
   

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

5. 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 (HILUX_TGN26 RM000000O8L0OLX.html).

   
   

   ECT

   Tester Display	Test Part	Control Range	Diagnostic Note
   Control the Shift Position	Operate shift solenoid valves and set each shift position	Press "→" button: Shift up Press "←" button: Shift down	Possible to check operation of the shift solenoid valves. [Vehicle Condition] 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 up-shift must be performed with the accelerator pedal released.
      
   3. The 5th to 4th down-shift 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 TCM is shown in the Data List display on the intelligent tester.
      

   OK:

   Gear position changes in accordance with the tester command.
   

NOTICE:

1. Perform the test while the ATF temperature is between 50 and 80°C (122 and 176°F).
   
2. Be careful to prevent the hose of SST from interfering with the exhaust pipe.
   
3. Perform the test with the A/C 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.

1. Remove the test plug from the transmission case and connect SST.
   

SST

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

2. Connect the intelligent tester to the DLC3.
   

3. Start the engine and warm it up.
   

4. Measure the line pressure with SST.
   

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.
   

8. 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: OFF: Line pressure up (when Active Test "Activate the Solenoid (SLT)" is performed, TCM commands shift solenoid valve SLT to turn OFF) ON: No action (normal operation)	[Vehicle Condition] Vehicle stopped Engine 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 (HILUX_TGN26 RM000000W7B0P2X.html) 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.
   

1. Clear the DTC (HILUX_TGN26 RM000000W770U5X.html).
   

2. Check for DTC again after conducting the Monitor Drive Pattern (HILUX_TGN26 RM000000W7K0P5X.html).
   

   OK:

   No DTC output.