Parts for your 2017 Ford Focus-Crank angle sensor

2017 Ford Focus crank-angle-sensor: what it does and how to look after it

Yes, the 2017 Ford Focus is fitted with a crank-angle-sensor (commonly called a Crankshaft Position Sensor or CKP). Technical references including the Ford Workshop Manual (WSM, Section 303–14: Electronic Engine Controls), Ford/Motorcraft service wiring diagrams, and industry data from Autodata/Haynes list a CKP on all 2017 Focus engines (1.0L EcoBoost, 1.5L EcoBoost, 2.0L GDI, and RS). Without a CKP signal, the PCM can’t calculate engine speed or exact crank position, so the Focus won’t start or will stall—this is by design per Ford diagnostics for DTCs like P0335/P0339.

On the 2017 Ford Focus, the crank-angle-sensor reads a toothed wheel on the crankshaft and feeds a precise timing signal to the PCM. That signal is the heartbeat for fuel injection and ignition timing, helping the car start crisply, idle smoothly, and run efficiently. Depending on engine variant, the sensor sits near the crank pulley at the front or at the gearbox bellhousing end, either way it’s mounted close to the crank and reads the reluctor teeth as they pass.

There’s no scheduled replacement interval for the crank-angle-sensor—if it’s healthy, leave it be. As part of routine servicing, it’s smart to glance over the wiring loom and connector under the bonnet, especially if the car does lots of gravel or wet work. Keep the connector clean and dry, and avoid blasting the area with a pressure washer. Because the Focus uses a Hall-effect CKP, there’s no air-gap adjustment, if it’s faulty, it’s replaced.

• Common symptoms of a failing sensor: hard starting or no start, sudden stalling, erratic tacho, rough running, reduced power, and stored codes like P0335/P0339.
• Quick checks: scan live data for engine rpm during crank, wiggle-test the harness, and inspect for oil or impact damage around the mount.

Replacement is straightforward for a competent DIYer with basic tools, though access varies by engine. Expect to remove trims or the airbox for room, unplug the connector, undo a single retaining bolt, and withdraw the sensor. Lightly oil the new O-ring, seat it square, and tighten the bolt to the workshop-manual torque. Clear fault codes and road test. Most Focus models don’t need a special relearn after CKP replacement, but follow WSM steps if prompted by your scan tool. Use a quality OEM-spec sensor—cheap copies can cause intermittent no-starts that’ll drive anyone spare.

FAQs

Does a 2017 Ford Focus have a crank-angle-sensor?
Absolutely. Ford documentation and wiring diagrams show a crankshaft position (crank-angle) sensor across all 2017 Focus engines. It’s essential for engine speed and timing inputs to the PCM.

What are the signs the crank-angle-sensor is failing on a 2017 Focus?
Typical tell-tales are a no-start or random stalling, a dead or jumpy tacho, rough idle, and fault codes such as P0335/P0339. Live data showing zero rpm while cranking is a big clue.

Can you drive with a dodgy crank-angle-sensor?
It might run intermittently, but it can cut out without warning and may leave you stranded. It’s best to diagnose promptly and replace the sensor or repair the wiring before it escalates.