Parts for your 2017 Nissan Pulsar-Knock sensor

2017 Nissan Pulsar knock sensor — what it does and when to replace it

Technical sources confirm the 2017 Nissan Pulsar is fitted with a knock sensor. The Nissan factory service manual for the B17 Pulsar/Sylphy/Sentra (Engine Control section, “Knock Sensor”) describes the sensor, its signal processing and diagnostic routines. Nissan’s FAST parts catalogue lists a Sensor Assy – Knock for MR18DE and MR16DDT engines used in 2013–2017 models. Independent data platforms commonly used in workshops, including Autodata and HaynesPro, also specify a knock sensor and associated DTCs such as P0325/P0328 for these engines.

On the 2017 Pulsar, the knock sensor quietly listens for detonation (pinging) through vibrations in the engine block. When it hears that tell-tale rattle, it signals the ECU to trim ignition timing and protect the engine. The upshot is smoother running on Aussie and Kiwi fuel grades, better fuel economy, and lower risk of long-term internal damage, especially under load or on hot days.

There’s no routine replacement interval for the knock sensor, but it deserves a spot on the servicing checklist. Good practice is to scan for fault codes at each service, visually check the sensor connector and loom for oil soak, brittleness or chafing, and ensure the sensor’s mounting isn’t disturbed. If it must be removed, it should go back on clean and torqued to the factory spec in the Nissan manual — over- or under-tightening can deaden its “hearing”.

If the Pulsar logs a knock-sensor code or shows tell-tale behaviour, get onto it early. Common signs include:

• Check Engine Light with codes like P0325/P0328
• Sluggish performance or heavier fuel use as the ECU plays it safe
• Audible pinging under load (especially uphill or with the air-con on)

Replacement is straightforward for a trained tech. The sensor is mounted to the block (typically beneath the intake side), and access varies with engine and tooling. A genuine or high-quality OEM-equivalent part is worth it — cheap copies can skew readings. After fitting, clear codes and verify with a road test and live-data check to confirm knock activity and timing control look normal.

Owners can also help the sensor help them: use decent-quality petrol, keep up with intake and cooling system maintenance, and fix any vacuum, PCV, or misfire issues promptly. The knock sensor is the engine’s early-warning mate — keep it healthy and the Pulsar will feel happier and more efficient day to day.

Where is the knock sensor on a 2017 Nissan Pulsar?

It’s bolted to the engine block, typically on the intake side around mid-block level. On the MR18DE, that means under the intake manifold area, where it can best “hear” block vibrations. Access usually involves working from above with the intake plumbing moved aside, or from underneath depending on tools and lift access.

Is it safe to drive with a faulty knock sensor?

It’ll usually run, but it’s not a great idea. The ECU may pull ignition timing to protect the engine, which makes the car feel flat and use more fuel. If real knock is present and the sensor can’t report it properly, there’s a risk of internal damage. Best to book it in and sort it sooner rather than later.

What does a failing knock sensor feel like on a Pulsar?

Many drivers notice a Check Engine Light first. Others feel reduced power, lazier throttle response, or hear light pinging on hills. A scan will confirm with codes such as P0325/P0328. Fixing wiring faults or replacing the sensor usually restores normal pep and economy.