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.

2021 Subaru Outback BaseFACTORY OEM SERVICE PROCEDURE

Symptom 5: Engine Does Not Start After Stop

Probable defective cause:

Starter circuit failure
Engine trouble
Judged the vehicle status as "Auto Start Stop restart cancel conditions are met".

CHECK AUTOSTART CANCEL CODE .
Check the autostart cancel code. Ref. to AUTO START STOP (DIAGNOSTICS)>AUTOSTART CANCEL CODE(S) DISPLAY .

Is autostart cancel code stored?

Yes: Check the appropriate item using the "List of Autostart Cancel Code". Ref. to AUTO START STOP (DIAGNOSTICS)>AUTOSTART CANCEL CODE(S) DISPLAY>OPERATION>LIST OF AUTOSTART CANCEL CODE .

No: Go to 2 .
CHECK DTC .
Read the DTC of [Engine] using the Subaru Select Monitor. Ref. to ENGINE (DIAGNOSTICS) (H4DO)>DIAGNOSTIC TROUBLE CODE (DTC) . Ref. to ENGINE (DIAGNOSTICS) (H4DOTC)>DIAGNOSTIC TROUBLE CODE (DTC) .

Are any DTCs displayed?

Yes: Perform the diagnosis according to the DTC. Ref. to ENGINE (DIAGNOSTICS) (H4DO)>DIAGNOSTIC TROUBLE CODE (DTC)>LIST . Ref. to ENGINE (DIAGNOSTICS) (H4DOTC)>DIAGNOSTIC TROUBLE CODE (DTC)>LIST .

No: The circuit has returned to a normal condition at this time. Reproduce the failure, and then perform the diagnosis again.

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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.