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.
DTC P0101: Mass Or Volume Air Flow Sensor "A" Circuit Range/Performance: Notes
1. -
DTC detecting condition:
Detected when two consecutive driving cycles with fault occur.
Trouble symptom:
- Improper idling
- Engine stall
- Poor driving performance
After the faulty parts are repaired or replaced, perform the final check in Basic Diagnostic Procedure. Ref. to ENGINE (DIAGNOSTICS) (H4DO(HEV))>BASIC DIAGNOSTIC PROCEDURE>PROCEDURE .
- CHECK DTC
.
Using the Subaru Select Monitor or a general scan tool, read the DTC of [Engine]. Ref. to COMMON (DIAG)>DIAGNOSTIC TROUBLE CODE (DTC) .
Is DTC other than P0101 displayed? (Current malfunction)
Yes: Check the appropriate DTC using the "Diagnostic Trouble Code (DTC)". Ref. to ENGINE (DIAGNOSTICS) (H4DO(HEV))>DIAGNOSTIC TROUBLE CODE (DTC) .
No: Replace the mass air flow and intake air temperature sensor. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO(HEV))>MASS AIR FLOW AND INTAKE AIR TEMPERATURE SENSOR .
NO RELATED
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.