Parts for your 2008 Subaru Forester-Crank angle sensor

2008 Subaru Forester crank angle sensor (crankshaft position sensor)

Yes, the 2008 Subaru Forester is fitted with a crank angle sensor, more commonly called the crankshaft position (CKP) sensor. Technical references that confirm its use include the Subaru Forester MY2008 Factory Service Manual (Engine H4SO Diagnostics, DTC P0335 Crankshaft Position Sensor “A” Circuit), Subaru’s Technical Information System (STIS), and the Subaru FAST electronic parts catalogue, which lists a CKP sensor for MY08 Forester EJ25 engines. Aftermarket service databases such as Autodata and ALLDATA also document CKP diagnostics and replacement for this model.

The crank angle sensor is the ECU’s timekeeper. Mounted near the front of the EJ25 engine, it reads a toothed wheel on the crank to report exact crank position and engine speed. That data lets the ECU fire spark and inject fuel at precisely the right moment. If the sensor goes out of whack, you’ll often see a check engine light (commonly P0335 or P0339), hard starting or a no-start, sudden stalling, misfires, rough idle, or the tacho dropping out. Because it’s a solid-state device, it isn’t a routine service item, but it is critical for reliable starting and smooth running.

For owners keeping their 2008 Subaru Forester in good nick, treat the crank angle sensor as “inspect and replace on condition.” During scheduled servicing, it’s smart to check the sensor connector for oil intrusion or green crust on the pins, make sure the loom isn’t rubbing on the timing cover, and fix any oil leaks that might wick into the plug. Electrical contact cleaner and a dab of dielectric grease on the seal can help keep moisture at bay.

Replacement is straightforward with basic tools. Disconnect the battery, unplug the sensor under the bonnet near the crank pulley, remove the single retaining bolt, and ease the sensor out. Lightly oil the new O-ring, seat the sensor squarely, and tighten the bolt to the factory spec. Use an OEM or reputable equivalent part, cheap copies can give flaky signals when hot. After fitting, clear any codes, then start and let it warm up. A short drive while watching for clean idle and no hesitation is a good check. No specific relearn is usually required on the EJ25, but if a code returns, inspect wiring continuity and engine earths before assuming the new sensor is dud.

• Common signs of trouble: P0335/P0339, no-start, random stalling, misfires, rough idle, tacho dropouts.
• Good practice: keep connectors clean and dry, protect the loom, fix oil leaks early.

Popular questions

Where is the crank angle sensor on a 2008 Forester?
On the EJ25 engine it’s mounted at the front of the engine block near the crankshaft pulley/timing cover, secured by a single small bolt and connected via a two-pin plug. Access is from the top with the bonnet open.

Do I need to program anything after replacing the sensor?
Typically, no. The ECU in the 2008 Forester learns crank signal alignment on the fly. After fitting the new sensor, clear stored fault codes, start the engine, and road test. If codes persist, check wiring and grounds.

Can a failing crank angle sensor be cleaned instead of replaced?
You can clean the connector and remove light debris from the sensor nose, but internal sensor faults are not repairable. If it’s intermittently cutting out when hot or throwing P0335/P0339, replacement is the reliable fix.