Parts for your 2004 Subaru Forester-Crank angle sensor

2004 Subaru Forester crank-angle sensor (crankshaft position sensor)

Based on technical references — including the Subaru Factory Service Manual for the 2004 Forester (EJ-series petrol engines), Subaru’s Technical Information System workshop procedures, and OEM parts catalogues — this model is fitted with a crank-angle sensor, more commonly listed as the crankshaft position sensor (CKP). It’s used across 2004 Forester variants, both the naturally aspirated 2.5 and the turbo XT, and is critical to engine management.

The crank-angle sensor’s job is to read the crankshaft’s position and speed from a toothed reluctor, sending a clean timing signal to the ECU. That signal lets the ECU line up fuel injection and spark at exactly the right moment. If the CKP signal drops out or goes noisy, the ECU loses sync — which can mean long cranking, random stalling, rough running, or a no-start with an engine light and codes like P0335/P0336.

There’s no scheduled replacement for the sensor, it’s a solid-state part designed to last. As part of routine servicing, it pays to:

• Visually check the sensor body and connector for heat damage, oil contamination, or corrosion.
• Inspect the wiring loom for chafing near the front of the engine and around the alternator.
• If diagnosing intermittent cut-out, review live-data crank RPM during cranking and check for stored CKP-related fault codes.

Replacement is straightforward and suits a competent DIYer or any workshop. Disconnect the battery, unplug the sensor, remove the retaining bolt, and withdraw the sensor. Fit the new unit with a lightly oiled O-ring, route the harness correctly, and snug the fastener to spec. Clear codes and confirm a clean crank signal on a scan tool during a test drive. No programming is required on these EJ engines, but allowing the car to idle and settle after battery reconnection is a good habit.

When is it worth proactive replacement? If the vehicle is showing hot-soak no-starts, tach drops to zero while cranking, or recurring stalling with CKP codes, go ahead. On higher-kilometre Foresters, many techs also inspect or pre-emptively replace the sensor when chasing intermittent misfires that don’t trace to coils, plugs, or fuel. Genuine or high-quality aftermarket sensors tend to produce the most stable signal and fewer comebacks.

Quick tells that the CKP may be the culprit:

• Cranks but won’t fire, especially when hot.
• Stalls at idle with immediate restart needed.
• Engine light with P0335/P0336 and no obvious ignition or fuel faults.

Popular questions about the 2004 Subaru Forester crank-angle sensor

Where is the crank-angle sensor on a 2004 Subaru Forester?
On EJ25 and EJ255 engines it sits at the front of the engine, mounted into the top of the block near the crank timing area, just behind the alternator and above the timing cover. It’s held by a single small bolt and uses a two-wire plug.

Access is from the top with the engine cover (if fitted) out of the way. Most techs can reach it without removing the timing covers.

Can a bad crank-angle sensor cause a no-start?
Absolutely. If the ECU doesn’t see a valid crank signal, it can’t trigger fuel or spark, so you’ll get a crank-no-fire. Often the tachometer won’t flicker during cranking, and a scan will show P0335.

Intermittent sensors may start working again once cooled, which is why some failures show up only after a warm soak.

Does a new sensor need programming?
No coding is required on the 2004 Forester’s EJ engines. It’s plug-and-play. After install, clear any stored codes and road test while watching live data for a stable RPM signal.

It’s sensible to let the engine idle for a few minutes post-install so trims settle, especially if the battery was disconnected.