DTC P0973: Shift Solenoid "A" Control Circuit Low: Notes

-
DTC detecting condition:

Immediately at fault recognition

Trouble symptom:

Gear is not changed. (No up-shift)

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. Ref. 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. Ref. 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:
  
  NOTE: The resistance value increase as the temperature increases.
  
  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 (OPEN CIRCUIT).
1. Disconnect the control valve body connector.
2. Measure the resistance between TCM connector and control valve body connector.
Connector & terminal

(T10) No. 48 - (T11) No. 10:

Is the resistance less than 1 Ω?

Yes: Go to 5.

No: Repair or replace the harness.
CHECK TRANSMISSION HARNESS (SHORT TO POWER SUPPLY).
1. Turn the ignition switch to ON.
2. Measure the voltage between TCM connector and transmission body.
Connector & terminal

(T10) No. 48 (+) - Transmission body (-):

Is the voltage approx. 0 V?

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

No: Repair or replace the harness.