Parts for your 2013 Subaru Legacy-Camshaft sensor

2013 Subaru Legacy camshaft sensor: purpose, care and replacement

Yes, the 2013 Subaru Legacy uses a camshaft position sensor. This is confirmed by Subaru’s factory service manual for the 2013 Legacy/Outback, which includes diagnostics for the camshaft position sensor, and by Subaru’s OEM parts catalog listing sensors for FB25 2.5-litre and EZ36 3.6-litre engines. Independent technical databases used by workshops also specify cam sensors on these engines for AVCS (variable valve timing) control and sequential fuel injection.

The camshaft sensor on a 2013 Legacy is a small, solid-state (Hall-effect) unit that reads a toothed trigger on the camshaft to tell the ECU exactly where the cam is in its rotation. That info lets the ECU fire injectors sequentially, manage ignition timing, and command the AVCS to shift cam timing for better torque, economy and emissions. If the sensor signal drops out or goes noisy, owners may see a check engine light, longer cranking, rough idle, flat spots under load, or the car defaulting to a limp strategy.

It’s not a scheduled service item, but during regular servicing it’s smart to check the sensor connectors for corrosion, brittle wiring near the plug, and any oil weeping from the sensor’s O-ring. Oil on the plug or harness can cause signal issues over time. Subaru’s design typically uses one bolt and an O-ring seal, so if it’s ever removed, a fresh O-ring lightly oiled makes refitting clean and leak-free.

• Common symptoms when failing: hard starting, erratic idle, misfires, poor fuel economy, and fault codes like P0340/P0341.
• Likely causes: internal sensor failure, damaged wiring, loose or oily connector, or metal debris on the sensor tip.

Replacement is straightforward for most home mechanics with a basic spanner set. Access differs by engine: on the FB25 boxer four there are sensors on the cylinder heads, on the EZ36 six there’s a sensor per bank. Always confirm bank and sensor location in a reliable workshop guide. Disconnect the battery, unplug the connector, remove the retaining bolt, twist the sensor gently to free the O-ring, and lift it out. Clean the bore, fit the new O-ring, seat the sensor squarely, and snug the bolt to manufacturer spec. Reconnect, clear any fault codes, and take a short test drive so the ECU can relearn trims. For stubborn or intermittent faults, a proper scope trace and wiring check under the bonnet will save time and guesswork.

FAQs

Where is the camshaft sensor on a 2013 Subaru Legacy?
On FB25 models it’s mounted on the cylinder head, typically toward the front or rear depending on bank, reading a cam trigger. On EZ36 3.6-litre models there’s one on each bank. Space is tight near the strut towers, but access is usually doable from above with the airbox or covers shifted.

What fault codes point to a bad camshaft sensor?
Common DTCs include P0340 (camshaft position circuit) and P0341 (range/performance). These can also be caused by wiring issues, poor connections, or timing concerns, so it’s worth checking the plug and harness before fitting a new sensor.

Should both cam sensors be replaced at once?
Not necessarily. Replace the sensor on the affected bank after confirming the diagnosis. If the vehicle has very high kilometres or multiple intermittent cam-related codes, replacing both and inspecting the harness can be sensible preventative maintenance.