Parts for your 2009 Ford Focus-Crank angle sensor

2009 Ford Focus crank-angle sensor (crankshaft position sensor)

For the 2009 Ford Focus, a crank-angle sensor is definitely relevant and fitted. Ford’s own Workshop Manual for the 2009 Focus lists the Crankshaft Position (CKP) sensor within the Electronic Engine Controls and provides removal/installation procedures, and mainstream references such as Haynes and Autodata catalog the CKP for the 1.6, 1.8 and 2.0 Duratec petrol engines as well as the diesel and performance variants. In short, this Focus generation uses a CKP to run the engine management.

On this model, the crank-angle sensor (often called a CKP) keeps the engine computer (PCM) in the loop on exactly where the crankshaft is in its rotation. It reads the toothed wheel on the crank to pinpoint top dead centre and rotational speed. The PCM then times fuel injection and spark to the millisecond, so the car starts crisply, idles smoothly, and pulls cleanly through the revs.

It’s not a scheduled service item, but it’s smart to give it some love during regular servicing. A quick visual check under the bonnet for chafed wiring, a loose connector, or oil contamination around the sensor mount can save a headache later. Many 2009 Focus variants mount the CKP low on the block by the gearbox bellhousing (reading the flywheel), others are near the crank pulley. Either way, road grime and the odd oil weep can build up.

What tells a driver the CKP is on the way out? Classic symptoms include:

• Hard starting or an intermittent no-start when hot
• Random stalling or misfiring under load
• Tachometer dropouts and limp-home behaviour
• Fault codes such as P0335–P0339

Replacement is straightforward for a competent home mechanic. Disconnect the battery, raise and support the car safely, locate the sensor, unplug the connector, and remove the single retaining bolt. Lightly oil the new O-ring, seat the new sensor squarely, and snug the bolt to spec. Use a quality OEM-equivalent sensor, cheapies can cause signal noise. After refit, clear any codes, check live data for stable RPM signal, and let the PCM relearn idle with a short drive cycle. A relearn procedure is usually not mandatory on these Fords, as the PCM self-adapts, but a clean idle learn helps.

Pro tips:

• Keep the mating face clean and avoid pulling the sensor against metal filings stuck to the magnet.
• Inspect the harness routing so it doesn’t rub on the driveshaft or subframe.
• If oil leaks are present, fix the leak to protect the new sensor and connector.

Popular questions

Where is the crank-angle sensor on a 2009 Ford Focus?
Most 2.0 Duratec petrol models place it low on the rear of the engine by the gearbox bellhousing where it reads the flywheel. Some variants position it at the front near the crank pulley. Look for a small two- or three-wire sensor held by a single bolt with a short loom to the engine harness.

What are common signs the CKP is failing on a 2009 Focus?
Hot no-starts, sudden stalls, rough idle, misfires, and a dead tach needle are common. The check engine light may log P0335–P0339. If the Focus starts fine cold but plays up warm, the CKP is a prime suspect.

Can the sensor be cleaned, or does it need replacing?
If it’s just light grime or metallic fuzz on the tip, a careful clean can restore a clean signal. But if the internal Hall/inductive element is failing or the wiring is damaged, replacement is the reliable fix.