Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
DTC P0951: Auto Shift Manual Control Circuit Range/Performance: Notes
1. -
DTC detecting condition:
Immediately at fault recognition
Trouble symptom:
Manual mode cannot be set.
Wiring diagram:
CVT control system Ref. to WIRING SYSTEM (IMPREZA MODEL)>CVT CONTROL SYSTEM .
- 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 .
- CHECK HARNESS
.
- Turn the ignition switch to OFF.
- Disconnect the manual mode switch connector.
- Measure the resistance between manual mode switch connector and chassis ground.
Connector & terminal
(i44) No. 8 - Chassis ground:
Is the resistance less than 1 Ω?
Yes: Go to 2.
No: Repair the open circuit of harness.
- CHECK MANUAL MODE SWITCH
.
Measure the resistance between manual mode switch terminals.
Terminals
No. 7 - No. 8:
Is the resistance 1 MΩ or more?
Yes: Go to 3.
No: Replace the select lever assembly. Ref. to CONTROL SYSTEMS>SELECT LEVER .
- CHECK MANUAL MODE SWITCH
.
- Shift the select lever to manual mode.
- Measure the resistance between manual mode switch terminals.
Terminals
No. 7 - No. 8:
Is the resistance less than 1 Ω?
Yes: Go to 4.
No: Replace the select lever assembly. Ref. to CONTROL SYSTEMS>SELECT LEVER .
- CHECK HARNESS
.
- Disconnect the TCM connector.
- Measure the resistance between TCM connector and manual mode switch connector.
Connector & terminal
(T10) No. 20 - (i44) No. 7:
Is the resistance less than 1 Ω?
Yes: Go to 5.
No: Repair the open circuit of harness or poor contact of connector.
- CHECK HARNESS
.
Measure the resistance between manual mode switch connector and chassis ground.
Connector & terminal
(i44) No. 7 - Chassis ground:
Is the resistance 1 MΩ or more?
Yes: Go to 6.
No: Repair the short circuit of harness.
- CHECK INPUT SIGNAL FOR TCM
.
- Connect all connectors.
- Turn the ignition switch to ON.
- Set the select lever to "D" range.
- Using the Subaru Select Monitor, read data of [Tiptronic Mode Switch] in the [Data Monitor] of [Transmission]. Ref. to TRANSMISSION (DIAGNOSTICS) (IMPREZA MODEL)>DATA MONITOR .
Does [Tiptronic Mode Switch] display [ON] with select lever in manual mode, and [OFF] with select lever in other than manual mode?
Yes: Current condition is normal.
No: Go to 7.
- CHECK FOR POOR CONTACT
.
Is there poor contact of the manual mode switch circuit?
Yes: Repair the poor contact.
No: Replace the TCM. Ref. to CONTINUOUSLY VARIABLE TRANSMISSION (TR580 IMPREZA)>TRANSMISSION CONTROL MODULE (TCM) .
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.