DTC P0971: Pressure Control Solenoid "C" Control Circuit High: Notes

DTC detecting condition: 

Immediately at fault recognition

Trouble symptom: 

• Tight corner braking phenomenon occurs.
• Driveability getting worse.
  CAUTION: Use the check board when measuring the TCM terminal voltage and resistance.

Wiring diagram: 

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

Courtesy of SUBARU OF AMERICA, INC.

1. CHECK HARNESS. 
   1. Turn the ignition switch to OFF.
   2. Disconnect the TCM connector.
   3. Disconnect the transmission connector.
   4. Measure the resistance between TCM connector and transmission connectors.

      Connector & terminal 

      (B54) No. 48 - (B11) No. 4:

   Is the resistance less than 1 Ω?

   Yes:  Go to  2.

   No:  Repair the open circuit of harness.

2. CHECK HARNESS. 
   1. Turn the ignition switch to ON.
   2. Measure the voltage between TCM connector and chassis ground.

      Connector & terminal 

      (B54) No. 48 (+) - Chassis ground (-):

   Is the voltage approx. 0 V?

   Yes:  Go to  3.

   No:  Repair the short circuit of harness.

3. CHECK AWD SOLENOID. 

   Measure the resistance between transmission connector and transmission body.

   Connector & terminal 

   (T4) No. 4 - Transmission body:

   Is the resistance approx. 2 - 4.5 Ω? (when cold)

   Yes:  Check for poor contact of connector, and if no fault is found, replace the TCM. Refer to CONTINUOUSLY VARIABLE TRANSMISSION (TR690)>TRANSMISSION CONTROL MODULE (TCM) .

   No:  Go to  4.

4. CHECK HARNESS INSIDE TRANSMISSION. 
   CAUTION: Start work after ATF cools down.
   1. Remove the transmission oil pan.
   2. Check for the harness pinch, damage.

   Is there any fault in the harness?

   Yes:  Replace the transmission harness.

   No:  Go to  5.

5. CHECK HARNESS INSIDE TRANSMISSION. 
   1. Disconnect the control valve body connector.
   2. Turn the ignition switch to ON.
   3. Measure the voltage between transmission connector and transmission body.

      Connector & terminal 

      (T4) No. 4 (+) - Transmission body (-):

   Is the voltage approx. 0 V?

   Yes:  Replace the control valve body. Refer to CONTINUOUSLY VARIABLE TRANSMISSION (TR690)>CONTROL VALVE BODY .

   No:  Replace the transmission harness.