Parts for your 2015 Ford Fiesta-Knock sensor

2015 Ford Fiesta Knock Sensor

Technical sources confirm that a knock sensor is fitted to 2015 Ford Fiesta petrol engines. Ford Workshop Manual (Fiesta 2014–2017, Engine Controls), details the Knock Sensor (base part 12A699) and related DTCs P0325–P0334, Ford ETIS/IDS wiring diagrams show the KS signal routed to the PCM, and Ford parts catalogues (Microcat) list the knock sensor for 2013–2017 Fiesta petrol variants, including 1.0 EcoBoost, 1.25/1.5/1.6 Duratec Ti-VCT and 1.6 EcoBoost ST. Aftermarket catalogues from OE suppliers also provide direct-fit knock sensors for these engines. Diesel variants typically don’t use a traditional knock sensor for spark control.

On a 2015 Ford Fiesta, the knock sensor is the quiet achiever that keeps the engine happy on Aussie and Kiwi fuel. It “listens” for detonation (pinging) and lets the PCM trim ignition timing to protect the engine and keep performance crisp. Whether it’s the punchy 1.0 EcoBoost or a naturally aspirated Duratec, the KS helps the car adapt to heat, load, and fuel quality without fuss.

There’s no scheduled maintenance for the knock sensor, but it’s worth a look during major services. A failing KS can trigger the MIL and store codes like P0325–P0334, and drivers might notice rattly pinging under load, flat acceleration, or higher fuel use. Because the sensor’s torque and mounting face are critical, replacing it is a precision job—over- or under-tightening can mess with its sensitivity.

Typical replacement approach for a Fiesta mechanic looks like this:

• Confirm the fault with scan data and DTCs, rule out fuel quality and intake/vacuum issues.
• Disconnect the battery, gain access (often beneath the intake side on the block).
• Inspect the harness and connector for oil ingress or chafing.
• Clean the block’s mating surface, install the new OE-quality sensor, torque to spec.
• Clear codes and road test under load to verify knock control activity.

Using top-tier 95/98 RON petrol can reduce knock events, but the sensor ensures the Fiesta stays protected even when conditions aren’t ideal. If the engine light’s on and there’s pinging or lazy throttle response, a proper diagnosis will quickly tell if the KS or its wiring is the culprit. Go genuine or OE-equivalent for best results, and don’t forget that correct routing of the loom helps avoid electrical noise.

Where is the knock sensor on a 2015 Ford Fiesta?

It’s bolted to the engine block, typically on the intake side. Access varies by engine, the 1.0 EcoBoost often needs intake components moved for a clear path. A workshop manual and a torch make life easier.

What are the signs of a bad knock sensor?

Common clues are the engine light on with codes like P0325–P0334, audible pinging under load, sluggish performance, or poorer fuel economy. Always check wiring and fuel quality before condemning the sensor.

Is it safe to drive with a faulty knock sensor?

The car usually runs, but the PCM may pull timing to protect the engine, so it’ll feel down on power and could use more fuel. Prolonged driving with real knock isn’t wise—get it diagnosed and sorted promptly.