DTC P0705: Transmission Range Sensor "A" Circuit (PRNDL Input): Notes

WARNING: This page is about a different car, the 2020 Subaru Impreza. However, it is still accessible from the selected car via links, so may be relevant.

1. -

DTC detecting condition:

Immediately at fault recognition

Trouble symptom:

Shift characteristics are erroneous.
The range position of the select lever and the position of shift indicator display do not match. Wiring diagram:

CVT control system Ref. to WIRING SYSTEM (IMPREZA MODEL)>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) (IMPREZA MODEL)>BASIC DIAGNOSTIC PROCEDURE .

Courtesy of SUBARU OF AMERICA, INC.

CHECK INPUT SIGNAL FOR TCM .
1. Turn the ignition switch to ON.
2. Move the select lever to each range, and read the data of [P Range], [R Range Signal], [N Range], [D Range Signal] in the [Data Monitor] of [Transmission] using the Subaru Select Monitor. Ref. to TRANSMISSION (DIAGNOSTICS) (IMPREZA MODEL)>DATA MONITOR .
Is the display of the range other than corresponding range [OFF]?

Yes : Go to 4.

No : Go to 2.
CHECK HARNESS .
1. Turn the ignition switch to OFF.
2. Disconnect the TCM connector.
3. Disconnect the inhibitor switch connector.
4. Measure the resistance between TCM connector and chassis ground.
  Connector & terminal
  
  (T10) No. 38 - Chassis ground:
  
  (T10) No. 37 - Chassis ground:
  
  (T10) No. 36 - Chassis ground:
  
  (T10) No. 35 - Chassis ground:
Is each resistance 1 MΩ or more?

Yes : Go to 3.

No : Repair the short circuit of transmission harness.
CHECK INHIBITOR SWITCH .
Move the select lever to each range, and measure the resistance between inhibitor switch terminals.

Terminals

No. 2 - No. 1:

No. 5 - No. 1:

No. 3 - No. 1:

No. 4 - No. 1:

Is the resistance other than corresponding range 1 MΩ or more?

Yes : Go to 4.

No : Replace the inhibitor switch. Ref. to CONTINUOUSLY VARIABLE TRANSMISSION (TR580 IMPREZA)>INHIBITOR SWITCH .
CHECK FOR POOR CONTACT .
Is there poor contact between TCM, inhibitor switch, transmission ground?

Yes : Repair the poor contact.

No : Replace the TCM. Ref. to CONTINUOUSLY VARIABLE TRANSMISSION (TR580 IMPREZA)>TRANSMISSION CONTROL MODULE (TCM) .