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
.
Ask the customer when and how the trouble occurred using the interview check list. Ref. to AUTO START STOP (DIAGNOSTICS)>CHECK LIST FOR INTERVIEW .
Did you interview the customer?
Yes : Go to 2.
No : Perform the interview, and Go to 2.
- CHECK Auto Start Stop OFF INDICATOR
.
Does the Auto Start Stop warning light (yellow) illuminate?
Yes : Go to 3.
No : Check the combination meter. Ref. to COMBINATION METER (DIAGNOSTICS)>ACTIVE TEST .
- CHECK SUBARU SELECT MONITOR COMMUNICATION
.
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
.
Read the DTC of [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 the DTC. After diagnosis, Go to 5.
No : Perform diagnosis according to the procedures in the diagnostics with phenomenon. Ref. to AUTO START STOP (DIAGNOSTICS)>DIAGNOSTICS WITH PHENOMENON .
- PERFORM DIAGNOSIS
.
- Using the Subaru Select Monitor, perform the clear memory of [Auto Start Stop]. Ref. to COMMON (DIAGNOSTICS)>CLEAR MEMORY .
- Execute the inspection mode. Ref. to AUTO START STOP (DIAGNOSTICS)>INSPECTION MODE .
- Read the DTC of [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 the 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.
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.
Rather have a pro handle this?
A certified mobile mechanic comes to your home or office. They bring the tools, you stay comfortable. No tow truck, no waiting room, no surprises.
No obligation. See pricing before you book.