DTC P0746 Pressure Control Solenoid "A" Performance/Stuck Off: Notes

DTC detecting condition: 

Detected when two consecutive driving cycles with fault occur.

Trouble symptom: 

• Shift control malfunction
• CVT chain slippage

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 (A) 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 P0746, is any of the DTCs P0842, P0843, P0962 and P0963 displayed?

   • Yes  : Perform the diagnosis according to DTCs other than P0746.
   • No  : Go to 2. 
2. CHECK SECONDARY SOLENOID (ACTIVE TEST). 
   1. Turn the ignition switch to ON.
   2. Using the Subaru Select Monitor, perform forced operation of the secondary 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 SECONDARY 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. 6 - Transmission body:

      Turbo model 

      (T4) No. 5 - Transmission body:

   Is the resistance approximately 5 - 7 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. 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 [Actual Secondary Pressure] 0.5 - 1.5 MPa?

   • Yes  : Go to 8. 
   • No  : Replace the control valve body. Ref. to CONTINUOUSLY VARIABLE TRANSMISSION(TR580)>Control Valve Body . Ref. to CONTINUOUSLY VARIABLE TRANSMISSION(TR690)>Control Valve Body .
8. CHECK INPUT SIGNAL FOR TCM. 
   1. Keep the engine speed at 3000 RPM.
   2. Read the data of [Actual Secondary Pressure] using Subaru Select Monitor.

   Is [Actual Secondary Pressure] higher than that of step 7? Does the value change according to the engine speed? And is the value 1.5 - 2.5 MPa?

   • Yes  : Go to 9. 
   • No  : Replace the control valve body. Ref. to CONTINUOUSLY VARIABLE TRANSMISSION(TR580)>Control Valve Body . Ref. to CONTINUOUSLY VARIABLE TRANSMISSION(TR690)>Control Valve Body .
9. CHECK TCM INPUT SIGNAL (STALL TEST). 
   1. Apply the parking brake.
   2. Set the select lever to "D" range.
   3. Depress the brake pedal firmly.
   4. Slowly open the accelerator fully, and stabilize the engine speed.
   5. Read the data of [Actual Secondary Pressure] using Subaru Select Monitor.
      CAUTION: Do not perform a stall test for over 5 seconds at a time.

   Is [Actual Secondary Pressure] higher than that of step 8? Does the value change according to the engine speed? And is the value 4.5 - 6.0 MPa?

   • Yes  : Go to 10. 
   • No  : Replace the control valve body. Ref. to CONTINUOUSLY VARIABLE TRANSMISSION(TR580)>Control Valve Body . Ref. to CONTINUOUSLY VARIABLE TRANSMISSION(TR690)>Control Valve Body .
10. 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 P0746 displayed?

    • Yes  : Perform the secondary pressure test. Ref. to CONTINUOUSLY VARIABLE TRANSMISSION(TR580)>Secondary Pressure (Line Pressure) Test . Ref. to CONTINUOUSLY VARIABLE TRANSMISSION(TR690)>Secondary Pressure (Line Pressure) Test .
    • No  : Current condition is normal. It is possible that temporary poor contact occurs.