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

-
DTC detecting condition:

Immediately at fault recognition

Trouble symptom:
- Tight corner braking phenomenon occurs.
- Drivability getting worse.
Wiring diagram:

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

Courtesy of SUBARU OF AMERICA, INC.

CAUTION:

Use CHECK BOARD when measuring the TCM terminal voltage and resistance.
After servicing or replacing faulty parts, perform the last step of the basic diagnostic procedure. Ref. to TRANSMISSION (DIAGNOSTICS)>BASIC DIAGNOSTIC PROCEDURE .

CHECK AWD SOLENOID (WHEN THE ENGINE IS COLD: ATF TEMPERATURE APPROX. 20°C).
1. Using the Subaru Select Monitor, check that [ATF Temp.] in [Data Monitor] of [Transmission] is 20°C. Refer to Data Monitor .
2. Turn the ignition switch to OFF.
3. Disconnect the TCM connector.
4. Measure the resistance between TCM connector and transmission body.
  Connector & terminal
  
  (T10) No. 48 - Transmission body:
  
  Is the resistance approximately 1.5 - 4.9 Ω?
  
  Yes: Go to 2.
  
  No: Go to 3.
CHECK AWD SOLENOID (WHEN THE ENGINE IS WARMED-UP: ATF TEMPERATURE 80°C OR MORE).
1. Connect the TCM connector.
2. Using the Subaru Select Monitor, check that [ATF Temp.] in [Data Monitor] of [Transmission] is 20°C. Refer to Data Monitor .
3. Turn the ignition switch to OFF.
4. Disconnect the TCM connector.
5. Measure the resistance between TCM connector and transmission body.
  Connector & terminal
  
  (T10) No. 48 - Transmission body:
  
  Is the resistance 1 MΩ or more?
  
  Yes: Go to 3.
  
  No: Check for poor contact of connector, and if no fault is found, replace the TCM. Ref. to CONTINUOUSLY VARIABLE TRANSMISSION (TR580)>TRANSMISSION CONTROL MODULE (TCM) .
CHECK HARNESS INSIDE TRANSMISSION.
CAUTION: Start work after ATF cools down.
1. Remove the transmission valve cover.
2. Check for the harness pinch, damage.
  Is the check result OK?
  
  Yes: Go to 4.
  
  No: Repair or replace the harness.
CHECK TRANSMISSION HARNESS (SHORT TO GROUND).
1. Disconnect the control valve body connector.
2. Measure the resistance between TCM connector and chassis ground.
Is the resistance 1 MΩ or more?

Yes: Replace the control valve body. Refer to CONTINUOUSLY VARIABLE TRANSMISSION (TR580)>TRANSMISSION CONTROL MODULE (TCM) .

No: Repair or replace the harness.