Parts for your 2012 Subaru Forester-Camshaft sensor

2012 Subaru Forester Camshaft Sensor

Based on technical references including the Subaru Factory Service Manual (2012MY Forester, Engine Diagnostics for DTCs P0340/P0345/P0341/P0346) and Subaru OEM parts catalogues, the 2012 Subaru Forester is fitted with camshaft position sensors. Both the FB25 2.5i and the EJ255 XT engines use camshaft position sensors (CMP), with one sensor on each cylinder bank. It’s absolutely relevant to this model’s engine management and variable valve timing.

The camshaft sensor tells the ECU exactly where each cam is in its rotation. That information lets the ECU run sequential fuel injection, control ignition timing, and command AVCS (Subaru’s variable valve timing) smoothly. When a CMP goes out of spec, the Forester can be harder to start, run rough, drop into limp mode, and turn on the check engine light with codes like P0340/P0345. Fuel economy and performance can both take a hit.

The sensor itself is a solid-state Hall-effect unit and isn’t a routine “wear” item, so there’s no set replacement interval. As part of regular servicing, it’s smart to:

• Inspect the wiring looms to both cylinder heads for rubbing, heat damage, or oil contamination near the rocker/cam covers.
• Check the connectors for corrosion, clean with proper electrical contact cleaner and re-seat.
• Look for oil wicking through a hardened sensor O-ring and replace the O-ring if needed.

Replacement is straightforward for a workshop or capable home mechanic under the bonnet. After disconnecting the battery, remove any covers for access, unplug the sensor on the affected bank, undo the single retaining bolt, and pull the sensor straight out. Lightly oil the new O-ring, seat the new sensor squarely, and tighten the bolt to the factory torque spec from the service manual (don’t overtighten a small M6 fastener). Clear fault codes, perform an idle relearn if required, and road test. Using a quality OEM-equivalent sensor is recommended, cheap units can cause intermittent faults that are hard to chase.

A note for this Forester: there are two CMP sensors—one per bank—so diagnosis should confirm the correct side before parts are ordered. Common symptoms that point to CMP issues include extended cranking, misfires on cold start, sudden stalling at idle, and the ECU logging cam/crank correlation codes.

Popular questions about the 2012 Subaru Forester camshaft sensor

Where is the camshaft sensor located on a 2012 Forester?
The 2012 Forester has a sensor on each cylinder bank, mounted to the cylinder head near the cam gear/rocker cover area. Access varies slightly between the FB25 and EJ255, but both are under the bonnet at the ends of the heads, retained by a single small bolt with an electrical connector.

Because space can be tight near the bulkhead on one side, removing the plastic engine cover and moving a hose or two often makes life easier. Always confirm bank and sensor location against the service manual for the exact engine.

What are the symptoms of a failing camshaft sensor on this model?
Typical behaviour includes hard starting, rough idle, reduced power, and the check engine light. The ECU may log P0340/P0341 (bank 1) or P0345/P0346 (bank 2) and sometimes cam/crank correlation codes. Fuel economy can drop, and the car may enter a limp mode to protect the engine.

Intermittent wiring faults can mimic a bad sensor, so a quick loom and connector check under the bonnet is worth doing before replacing parts.

Should the camshaft sensor be replaced as routine maintenance?
No fixed interval is specified, the sensor is replaced on condition. During regular servicing, technicians should inspect wiring, connectors and O-rings, and act if there are oil leaks, corrosion or stored cam-related fault codes.

If replacement is needed, using an OEM or reputable brand sensor helps avoid repeat issues, and clearing codes plus an idle relearn will get the Forester back to smooth running.