Parts for your 2018 Nissan Serena-Knock sensor

2018 Nissan Serena knock sensor

Yes, the 2018 Nissan Serena is fitted with a knock sensor. Nissan’s C27 Serena Service Manual (EC – Engine Control) lists the knock sensor input used by the ECM for ignition control and includes related diagnostic trouble codes P0325, P0327 and P0328, confirming its presence. The MR20DD 2.0‑litre petrol and the e‑POWER’s HR12DE generator engine both show a block‑mounted knock sensor in Nissan technical literature (EC/EM sections), used to detect detonation and adjust timing.

The knock sensor on a 2018 Serena quietly keeps the engine safe and smooth. It listens for pinging (detonation) through a piezo element bolted to the cylinder block. When the ECM “hears” knock, it tweaks ignition timing and fuelling so the engine can run happily on our local fuels and varying temperatures, without risking piston or bearing damage. It’s a big deal for fuel economy, torque under load, and emissions, especially in a people mover that sees plenty of family kms.

As a servicing item, the knock sensor isn’t something that’s routinely replaced on a schedule. What matters is condition and signal quality. During regular services, a tech will:

• Scan for DTCs like P0325/P0327/P0328 and check live data for noisy or flat signals.
• Inspect the loom and connector for oil soak, heat hardening or damaged shielding.
• Confirm the sensor is correctly seated and tightened to the specified torque (follow Nissan specs).

If the Serena shows a check‑engine light, rattly pinging under load, sluggish performance, or rising fuel use, a tired knock sensor or wiring fault could be in the mix. Keep in mind, genuine engine knock can also be caused by poor‑quality fuel, heavy carbon build‑up, or a timing issue, so proper diagnosis is key.

Replacement is straightforward but fiddly for access. On MR20DD models it’s mounted on the block beneath the intake side, on e‑POWER HR12DE it sits low on the block. Battery off, connector off, sensor out, fit the new one clean and dry, and torque it correctly. Don’t use sealants or tape on the mating face or bolt. After refit, clear codes, check for any new DTCs, and perform any required idle or ECM learning procedures with a scan tool.

Using a quality, Serena‑correct sensor and keeping the harness tidy helps the ECM keep timing spot‑on, which means smoother pulling power and better economy across Aussie and Kiwi conditions.

Popular questions

Where is the knock sensor located on a 2018 Nissan Serena?

On MR20DD petrol models it’s bolted to the engine block on the intake side, roughly mid‑block beneath the manifold. On e‑POWER (HR12DE) it’s mounted low on the block. Access can be from above with intake components moved, or from underneath depending on tools and hoist access.

What symptoms or codes point to a bad knock sensor?

Common signs include a check‑engine light, reduced power, flat spots on acceleration, worse fuel economy, or audible pinging. Typical ECM codes are P0325 (knock sensor circuit), P0327 (low input) and P0328 (high input). Always confirm wiring integrity and fuel quality before replacing the sensor.

Does the knock sensor need regular replacement?

No, it’s not a scheduled maintenance item. Replace it if diagnostics confirm a fault. During services, checking for stored DTCs and inspecting the sensor harness and mounting is usually sufficient to keep it reliable over high kilometres.