DTC P0776 Pressure Control Solenoid "B" Performance/Stuck Off: Notes

DTC detecting condition: 

Detected when two consecutive driving cycles with fault occur.

Trouble symptom: 

• Engine speed increases abruptly, and can not accelerate.
• Excessive slippage is felt.

Wiring diagram: 

• Non-turbo model

  CVT control system Ref. to WIRING SYSTEM>CVT Control System>WIRING DIAGRAM>NON-TURBO MODEL .

  Fig 1: Pressure Control Solenoid (B) Performance/Stuck OFF System Wiring Diagram (Non-Turbo Model)

  Courtesy of SUBARU OF AMERICA, INC.
• Turbo model

  CVT control system Ref. to WIRING SYSTEM>CVT Control System>WIRING DIAGRAM>TURBO MODEL .

1. CHECK DTC. 

   Read the DTC using Subaru Select Monitor.

   Besides DTC P0776, is any of the DTCs P0717, P0720, P0966, P0967, P2747 and P2751 displayed?

   • Yes  : Perform the diagnosis according to DTCs other than P0776.
   • No  : Go to 2. 
2. CHECK F&R SOLENOID (ACTIVE TEST). 
   1. Turn the ignition switch to ON.
   2. Using the Subaru Select Monitor, perform forced operation of the F&R solenoid. Ref. to TRANSMISSION (DIAGNOSTICS)>Active Test .

   Does the indication of 0 → 500 mA appear repeatedly during forced operation, and does operating sound emit during indicating 500 mA?

   • Yes  : Go to  5.
   • No  : Go to 3. 
3. CHECK F&R SOLENOID. 
   1. Turn the ignition switch to OFF.
   2. Disconnect the transmission connector.
   3. Measure the resistance between transmission connector and transmission body.

      Connector & terminal 

      Non-turbo model 

      (T4) No. 7 - Transmission body:

      Turbo model 

      (T4) No. 9 - Transmission body:

   Is the resistance approximately 4 - 6 Ω? (when cold)

   • Yes  : Go to  7.
   • No  : Go to 4. 
4. CHECK HARNESS. 

   Check the transmission harness. (Open circuit, short circuit to power supply, short circuit to ground, and poor contact)

   Is the check result OK?

   • Yes  : Go to  7.
   • No  : Repair the harness.
5. CHECK TRANSMISSION FLUID. 
   1. Connect the transmission connector.
   2. Check the amount of ATF. Ref. to CONTINUOUSLY VARIABLE TRANSMISSION(TR580)>CVTF>ADJUSTMENT . Ref. to CONTINUOUSLY VARIABLE TRANSMISSION(TR690)>CVTF>ADJUSTMENT .

   Is the check result OK?

   • Yes  : Go to 6. 
   • No  : Adjust the amount of ATF. Ref. to CONTINUOUSLY VARIABLE TRANSMISSION(TR580)>CVTF>ADJUSTMENT . Ref. to CONTINUOUSLY VARIABLE TRANSMISSION(TR690)>CVTF>ADJUSTMENT .
6. CHECK TRANSMISSION FLUID. 

   Check the condition of ATF. Ref. to CONTINUOUSLY VARIABLE TRANSMISSION(TR580)>CVTF>CONDITION CHECK . Ref. to CONTINUOUSLY VARIABLE TRANSMISSION(TR690)>CVTF>CONDITION CHECK .

   Is the check result OK?

   • Yes  : Go to 7. 
   • No  : Check according to the "Corrective action" of ATF (CVTF) "CONDITION CHECK". Ref. to CONTINUOUSLY VARIABLE TRANSMISSION(TR580)>CVTF>CONDITION CHECK . Ref. to CONTINUOUSLY VARIABLE TRANSMISSION(TR690)>CVTF>CONDITION CHECK .
7. CHECK INPUT SIGNAL FOR TCM. 
   1. Start the engine.
   2. Warm up until the ATF temperature reaches to 40 - 70°C (104 - 158°F).
   3. Depress the brake pedal, and shift the select lever to "D" range.
   4. Shift the select lever to "P" range.
   5. Stabilize the engine speed at idle.
   6. Read the data of [Actual Secondary Pressure] using Subaru Select Monitor.

   Is [Actual Secondary Pressure] 0.5 - 1.5 MPa?

   • Yes  : Go to 8. 
   • No  : Perform the diagnosis according to DTC P0841. Ref. to TRANSMISSION (DIAGNOSTICS)>Diagnostic Procedure with Diagnostic Trouble Code (DTC)>DTC P0841 TRANSMISSION FLUID PRESSURE SENSOR/SWITCH "A" CIRCUIT RANGE/PERFORMANCE .
8. STALL TEST. 

   Perform the stall test. Ref. to CONTINUOUSLY VARIABLE TRANSMISSION(TR580)>Stall Test . Ref. to CONTINUOUSLY VARIABLE TRANSMISSION(TR690)>Stall Test .

   Is the result of the stall test OK?

   • Yes  : Go to 9. 
   • No  : Replace the transmission assembly if the stall speed is higher than the standard value of the stall test. Ref. to CONTINUOUSLY VARIABLE TRANSMISSION(TR580)>Automatic Transmission Assembly . Ref. to CONTINUOUSLY VARIABLE TRANSMISSION(TR690)>Automatic Transmission Assembly .
9. DRIVING CHECK BY INSPECTION MODE. 
   1. Turn the ignition switch to OFF.
   2. Perform a drive check based on the "Inspection Mode". Ref. to TRANSMISSION (DIAGNOSTICS)>Inspection Mode .

   Does the AT OIL TEMP light blink and is DTC P0776 displayed?

   • Yes  : Replace the transmission assembly. Ref. to CONTINUOUSLY VARIABLE TRANSMISSION(TR580)>Automatic Transmission Assembly . Ref. to CONTINUOUSLY VARIABLE TRANSMISSION(TR690)>Automatic Transmission Assembly .
   • No  : Current condition is normal. It is possible that temporary poor contact occurs.