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.
2012 Subaru Forester F4-2.5L DOHCFACTORY OEM SERVICE PROCEDURE
Air Flow Meter/Sensor: Testing and Inspection
MASS AIR FLOW AND INTAKE AIR TEMPERATURE SENSOR
INSPECTION
1. CHECK THE MASS AIR FLOW SENSOR UNIT
1. Connect the battery positive terminal to terminal No. 3 and the battery ground terminal to terminal No. 4, the circuit tester positive terminal to terminal No. 5 and the circuit tester ground terminal to terminal No. 4.
2. Check the voltage changes when air is blown to the mass air flow sensor unit in arrow direction.
2. CHECK THE INTAKE AIR TEMPERATURE SENSOR UNIT
Measure the resistance between intake air temperature sensor terminals.
3. OTHER INSPECTIONS
1. Check that the mass air flow and intake air temperature sensor has no deformation, cracks or other damages.
2. Check that the mass air flow and intake air temperature sensor has no dirt.
INSPECTION
1. CHECK THE MASS AIR FLOW SENSOR UNIT
1. Connect the battery positive terminal to terminal No. 3 and the battery ground terminal to terminal No. 4, the circuit tester positive terminal to terminal No. 5 and the circuit tester ground terminal to terminal No. 4.
2. Check the voltage changes when air is blown to the mass air flow sensor unit in arrow direction.
2. CHECK THE INTAKE AIR TEMPERATURE SENSOR UNIT
Measure the resistance between intake air temperature sensor terminals.
3. OTHER INSPECTIONS
1. Check that the mass air flow and intake air temperature sensor has no deformation, cracks or other damages.
2. Check that the mass air flow and intake air temperature sensor has no dirt.
Factory Service Tools
Use the Manual With the Right Hardware
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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.