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.
Basic Diagnostic Procedure: Procedure
- CHECK PRE-INSPECTION.
- Ask the customer when and how the trouble occurred using the Check List for Interview. Refer to CONTINUOUSLY VARIABLE TRANSMISSION (DIAGNOSTICS)>CHECK LIST FOR INTERVIEW .
- Before performing diagnostics, check the following items which might affect CVT problems.
- General inspection Refer to CONTINUOUSLY VARIABLE TRANSMISSION (DIAGNOSTICS)>GENERAL DESCRIPTION>INSPECTION .
- Disconnection of harness connector
- Visual check for harness damage
- Oil leakage
- Stall speed test Refer to CONTINUOUSLY VARIABLE TRANSMISSION(TR690)>STALL TEST .
- Secondary pressure test Refer to CONTINUOUSLY VARIABLE TRANSMISSION(TR690)>SECONDARY PRESSURE (LINE PRESSURE) TEST .
- Transfer clutch pressure test Refer to CONTINUOUSLY VARIABLE TRANSMISSION(TR690)>TRANSFER CLUTCH PRESSURE TEST .
- Time lag test Refer to CONTINUOUSLY VARIABLE TRANSMISSION(TR690)>TIME LAG TEST .
- Road test Refer to CONTINUOUSLY VARIABLE TRANSMISSION(TR690)>ROAD TEST .
- Inhibitor switch Refer to CONTINUOUSLY VARIABLE TRANSMISSION(TR690)>INHIBITOR SWITCH .
Is the check result OK?
Yes: Go to 2.
No: Repair the items which may be affecting the CVT trouble.
- CHECK AT OIL TEMP LIGHT.
Turn the ignition switch to ON and wait for at least 2 seconds.
Does the AT OIL TEMP light illuminate?
Yes: Go to 3.
No: Check the AT OIL TEMP light.
- CHECK AT OIL TEMP LIGHT.
Start the engine and wait for 2 seconds or more.
Does the AT OIL TEMP light blink?
Yes: Go to 4.
No: Go to 5.
- CHECK DTC DISPLAY.
Read the DTC.
NOTE: If the communication function of Subaru Select Monitor cannot be executed normally, check the communication circuit. Refer to CONTINUOUSLY VARIABLE TRANSMISSION (DIAGNOSTICS)>DIAGNOSTIC PROCEDURE FOR SUBARU SELECT MONITOR COMMUNICATION>COMMUNICATION FOR INITIALIZING IMPOSSIBLE .Is DTC displayed on Subaru Select Monitor?
Yes : Record the DTC, time stamp and freeze frame data.
Go to 6.
NOTE:- For the time stamp, refer to LAN information . Refer to LAN SYSTEM (DIAGNOSTICS)>GENERAL DESCRIPTION>CAUTION>TIME STAMP .
- Depending on DTCs, time stamp may not be stored.
No : Go to 5.
- PERFORM GENERAL DIAGNOSTICS.
- Inspect using "Diagnostic Procedure without Diagnostic Trouble Code (DTC)". Refer to CONTINUOUSLY VARIABLE TRANSMISSION (DIAGNOSTICS)>DIAGNOSTIC PROCEDURE WITHOUT DIAGNOSTIC TROUBLE CODE (DTC) .
- Inspect using "Diagnostics with Phenomenon". Refer to CONTINUOUSLY VARIABLE TRANSMISSION (DIAGNOSTICS)>DIAGNOSTICS WITH PHENOMENON .
- Perform the Inspection Mode. Refer to CONTINUOUSLY VARIABLE TRANSMISSION (DIAGNOSTICS)>INSPECTION MODE .
- Read the DTC.
Is DTC displayed on Subaru Select Monitor?
Yes : Go to 6.
No : Finish the diagnosis.
- PERFORM DIAGNOSIS.
- Inspect by referring to "Diagnostic Procedure with Diagnostic Trouble Code (DTC)". Refer to CONTINUOUSLY VARIABLE TRANSMISSION (DIAGNOSTICS)>DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC) .NOTE: For the DTC table, refer to "List of Diagnostic Trouble Code (DTC)". Refer to CONTINUOUSLY VARIABLE TRANSMISSION (DIAGNOSTICS)>LIST OF DIAGNOSTIC TROUBLE CODE (DTC) .
- Repair the trouble cause.
- Perform the Clear Memory Mode.
- Perform the Inspection Mode. Refer to CONTINUOUSLY VARIABLE TRANSMISSION (DIAGNOSTICS)>INSPECTION MODE .
- Read the DTC.
Is DTC displayed on Subaru Select Monitor?
Yes : Inspect by referring to "Diagnostic Procedure with Diagnostic Trouble Code (DTC)". Refer to CONTINUOUSLY VARIABLE TRANSMISSION (DIAGNOSTICS)>DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC) .
No : Finish the diagnosis.
- Inspect by referring to "Diagnostic Procedure with Diagnostic Trouble Code (DTC)". Refer to CONTINUOUSLY VARIABLE TRANSMISSION (DIAGNOSTICS)>DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC) .
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Disclosure: Verified tool recommendations may earn an affiliate commission at no cost to you.
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.