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
- PERFORM CUSTOMER INTERVIEW
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Ask the customer when and how the trouble occurred using the interview check list. Ref. to AUTO START STOP (DIAGNOSTICS)>CHECK LIST FOR INTERVIEW>CHECK .
Did you interview the customer?
Yes : Go to 2 .
No : Interview the customer. Ref. to AUTO START STOP (DIAGNOSTICS)>CHECK LIST FOR INTERVIEW>CHECK .
- CHECK Auto Start Stop OFF INDICATOR
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Does the Auto Start Stop warning light (yellow) illuminate?
Yes : Go to 3 .
No : Check the combination meter. Ref. to INSTRUMENTATION/DRIVER INFO>COMBINATION METER SYSTEM>OPERATION>SELF-DIAGNOSIS DISPLAY MODE .
- CHECK SUBARU SELECT MONITOR COMMUNICATION
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Check for communication with TCM.
NOTE: If the communication function of the Subaru Select Monitor cannot be executed properly, check the communication circuit. Ref. to AUTO START STOP (DIAGNOSTICS)>DIAGNOSTIC PROCEDURE FOR SUBARU SELECT MONITOR COMMUNICATION .Is communication possible?
Yes : Go to 4 .
No : Check the communication circuit. Ref. to AUTO START STOP (DIAGNOSTICS)>DIAGNOSTIC PROCEDURE FOR SUBARU SELECT MONITOR COMMUNICATION .
- CHECK DTC
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Read the DTC related to the Auto Start Stop using the Subaru Select Monitor. Ref. to AUTO START STOP (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC) .
Are any DTCs displayed?
Yes : Perform the diagnosis according to DTC. After diagnosis, Go to 5 .
No : Perform diagnosis according to the procedures in the diagnostics with phenomenon.
- PERFORM DIAGNOSIS
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- Using the Subaru Select Monitor, perform the clear memory. Ref. to COMMON (DIAG)>CLEAR MEMORY .
- Execute the inspection mode. Ref. to AUTO START STOP (DIAGNOSTICS)>INSPECTION MODE .
- Read the DTC using Subaru Select Monitor. Ref. to AUTO START STOP (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC) .
Are any DTCs displayed?
Yes : Perform the diagnosis according to DTC. Ref. to AUTO START STOP (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC)>LIST .
No : Finish the diagnosis.
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
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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.