DTC Troubleshooting: P0756
DTC P0756: Shift Solenoid Valve B Stuck OFF
NOTE:
Before you troubleshoot, review the General Troubleshooting Information.
If DTC P0756 is stored in the PCM, the transmission does not shift to any gear other than 2nd or 5th gear because of the fail-safe function.

DTC Description
Confirmed DTC
Pending DTC
Freeze Frame
P0756 Shift Solenoid Valve B Stuck OFF
      

1.
ATF check:

ATF check
?1.
Warm up the engine to normal operating temperature (the radiator fan comes on).

?2.
Make sure that the transmission is filled to the proper level, and check for fluid leaks.

?3.
Drain the ATF through a strainer. Inspect the strainer for metal debris or excessive clutch material.

Does the strainer have metal debris or excessive clutch material?

     
YES
     
     
     
     
NO
     
     
     
Replace the ATF, then go to step 2.
2.
Determine possible failure area (shift solenoid valve B, others):

Determine possible failure area (shift solenoid valve B, others)
?1.
Turn the vehicle to the ON mode.

?2.
Clear the DTC with the HDS.


?3.
Start the engine.

?4.
With the brake pedal pressed, shift to D position/mode, and check the parameter(s) below with the HDS.
Signal
Current conditions
Values
Unit
A/T Shift Sol VLV. B
    
Input Shaft (Mainshaft) Speed (rpm)
    
Shift Control
    

Is the Input Shaft (Mainshaft) Speed (rpm) 0 rpm when A/T Shift Sol VLV. B is OFF, and about the same as the engine speed when A/T Shift Sol VLV. B is ON?

     
YES
     
     
     
Shift to P position/mode, and go to step 4.
     
NO
     
     
     
Shift to P position/mode, and go to step 3.
3.
Problem verification:

Problem verification
?1.
Clear the DTC with the HDS.


?2.
With the brake pedal pressed, shift to D position/mode, and check the parameter(s) below with the HDS.
Signal
Current conditions
Values
Unit
A/T Shift Sol VLV. B
    
Input Shaft (Mainshaft) Speed (rpm)
    
Shift Control
    

Does the Input Shaft (Mainshaft) Speed (rpm) remain steady when A/T Shift Sol VLV. B is OFF and when it is ON?

     
YES
     
     
     
The failure is duplicated. Faulty 1st gear one-way clutch. Replace the countershaft 1st gear (1st gear one-way clutch) or the transmission. If replacing the countershaft 1st gear, clean off any metal debris or excessive clutch material inside the transmission, the ATF cooler, the ATF hoses, the ATF pipes, and the hydraulic circuit. Then, replace the countershaft 1st gear and the torque converter.?
     
NO
     
     
     
Intermittent failure, the system is OK at this time. If the freeze data/on-board snapshot of this DTC is recorded, try to reproduce the failure under the same conditions with the freeze data/on-board snapshot.?
4.
Shift solenoid valve B check:

Shift solenoid valve B check
?1.
Select Shift Solenoid Valve B in the Miscellaneous Test Menu, and check that shift solenoid valve B operates with the HDS.

  

Is a clicking sound heard?

     
YES
     
     
     
Shift solenoid valve B is OK. Go to step 5.
     
NO
     
     
     
5.
Shift valve B check:

Shift valve B check
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Raise the vehicle on a lift. Make sure it is securely supported, and allow all four wheels to rotate freely.

?3.
Turn the vehicle to the ON mode.

?4.
Clear the DTC with the HDS.


?5.
Start the engine.

?6.
Disable the VSA by pressing the VSA OFF button.

NOTE: Enter the VSA maintenance mode in case of the vehicle speed above 31 mph (50 km/h).

?7.
Test-drive the vehicle, and shift the transmission to 2nd gear, then to 3rd gear, and check the parameter(s) below with the HDS. Slow down, and stop the wheels.
Signal
Current conditions
Values
Unit
3rd Pressure Switch
    
6th Pressure Switch
    
Shift Control
    

In 3rd gear, was the 3rd Pressure Switch OFF and was the 6th Pressure Switch ON?

     
YES
     
     
     
     
NO
     
     
     
Shift valve B is OK. Faulty shift valve C. Replace the main valve body (shift valve C) or the transmission. If replacing the main valve body, clean off any metal debris or excessive clutch material inside the transmission, the ATF cooler, the ATF hoses, the ATF pipes, and the hydraulic circuit. Then, replace the main valve body and the torque converter.?