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: 

CVT control system Refer to WIRING SYSTEM>CVT CONTROL SYSTEM .

Courtesy of SUBARU OF AMERICA, INC.

1. CHECK DTC. 

   Read the DTC using Subaru Select Monitor.

   Besides DTC P0776, is any of the DTCs P0720, P0966, P0967, P1706 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. Refer to CONTINUOUSLY VARIABLE 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 

      (T4) No. 9 - Transmission body:

   Is the resistance approx. 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. Refer to CONTINUOUSLY VARIABLE TRANSMISSION (TR690)>CVTF>ADJUSTMENT .

   Is the check result OK?

   Yes:  Go to  6.

   No:  Adjust the amount of ATF. Refer to CONTINUOUSLY VARIABLE TRANSMISSION (TR690)>CVTF>ADJUSTMENT .

6. CHECK TRANSMISSION FLUID. 

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

7. CHECK INPUT SIGNAL FOR TCM. 
   1. Lift up the vehicle.
   2. Start the engine.
   3. Warm up until the ATF temperature reaches to 40 - 70°C (104 - 158°F).
   4. Depress the brake pedal, and shift the select lever to "D" range.
   5. Shift the select lever to "P" range.
   6. Stabilize the engine speed at idle.
   7. Read the data of «Actual Secondary Pressure» using Subaru Select Monitor.

   Is the «Actual Secondary Pressure» 0.5 - 1.5 MPa?

   Yes:  Go to  8.

   No:  Perform the diagnosis according to DTC P0841. Refer to CONTINUOUSLY VARIABLE 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. Refer 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. Refer 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". Refer to CONTINUOUSLY VARIABLE TRANSMISSION (DIAGNOSTICS)>INSPECTION MODE .

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

   Yes:  Replace the transmission assembly. Refer to CONTINUOUSLY VARIABLE TRANSMISSION (TR690)>AUTOMATIC TRANSMISSION ASSEMBLY .

   No:  Current condition is normal. It is possible that temporary poor contact occurs.