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.
2022 Subaru Ascent BaseFACTORY OEM SERVICE PROCEDURE
Inspection Mode Ab
| DTC | Description & trouble part | Condition | Number of driving cycles on the detecting condition |
|---|---|---|---|
| P0039 | TURBOCHARGER/SUPERCHARGER BYPASS VALVE "A" CONTROL CIRCUIT RANGE/PERFORMANCE | - | 2 |
| P0234 | TURBOCHARGER/SUPERCHARGER "A" OVERBOOST CONDITION | - | 2 |
| P0299 | TURBOCHARGER/SUPERCHARGER "A" UNDERBOOST CONDITION | - | 2 |
| P226B | TURBOCHARGER/SUPERCHARGER BOOST PRESSURE TOO HIGH - MECHANICAL | - | 1 |
WARNING:
When performing inspection mode AB on a public road, pay sufficient attention to the traffic condition and give the highest priority to safe driving.
Factory Service Tools
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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.
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