Parts for your 2020 Nissan Serena-Knock sensor

2020 Nissan Serena knock sensor: what it does and how to look after it

Referencing Nissan’s own technical literature confirms the 2020 Nissan Serena (C27) is fitted with a knock sensor. The C27 Electronic Service Manual (Engine Control/EC section) for both the MR20DD 2.0-litre S-HYBRID and the e-POWER variant (HR12DE range-extender engine) lists the Knock Sensor (KS) in component layouts, wiring diagrams and diagnostics, with DTCs such as P0325/P0328 documented. Nissan’s FAST/Global parts catalogue also shows a “SENSOR ASSY – KNOCK” for C27 Serena build years covering 2020. With those factory sources, a knock sensor is clearly relevant and used on this model.

On the 2020 Serena, the knock sensor is the quiet achiever. It listens for the tell-tale vibration of knock (detonation) in the engine block and feeds that signal to the ECM. The computer then trims ignition timing and fuelling in real time, protecting the engine and helping it run smoothly on varying fuel qualities. That means better drivability, improved efficiency and lower risk of internal damage under load or on hot days.

It isn’t a consumable item, so there’s no scheduled replacement. During regular servicing, a sensible workshop will simply keep an eye on the sensor and harness routing under the bonnet—checking for oil or coolant contamination, brittle conduit, or a loose connector. If the intake gear comes off for other work (like spark plugs on the MR20DD), it’s a good moment to look over the knock sensor wiring and ensure it’s clipped correctly.

Tell-tales that point to knock-sensor trouble include:

• Check Engine Light with codes like P0325/P0328
• Sluggish performance and higher fuel use (timing pulled back as a safeguard)
• Audible pinging under load if the signal isn’t reliable

Before replacing the sensor, proper diagnosis matters. A scan-tool check, a quick continuity test of the sub-harness, and a look for corrosion in the connector can save needless parts swapping. If the sensor is confirmed faulty, use a genuine-spec unit and follow the torque spec and tightening procedure in the Nissan ESM—over- or under-tightening can skew readings on these piezoelectric sensors. Keep the mating surface clean, route the loom exactly as per the manual, clear the DTCs, and perform a decent road test with some load so the ECM’s knock learn adapts.

For the e-POWER Serena, even though the petrol engine drives a generator rather than the wheels, the knock sensor is just as important—it lets the ECM keep the small engine happy and efficient while it hums away in the background.

FAQs

Where is the knock sensor on a 2020 Serena?
It’s mounted to the engine block beneath the intake side, roughly mid-block. Access typically involves removing intake ducting and related covers, exact reach depends on whether it’s the MR20DD S-HYBRID or the e-POWER range-extender engine. A workshop manual view makes location and loom routing much easier.

Is it safe to drive with a bad knock sensor?
The ECM usually defaults to conservative timing, so the vehicle will run, but with dull performance and higher fuel use. Persisting can mask real knock events and isn’t ideal for engine longevity. Best practice is to diagnose and repair promptly.

What does replacement usually cost?
In Australia and New Zealand, expect parts in the ballpark of a couple of hundred dollars, with labour typically under two hours depending on engine and access. All up, many jobs land somewhere in the mid-hundreds. A firm quote needs the exact variant and workshop rates.