Parts for your 2008 Nissan Serena-Knock sensor

2008 Nissan Serena knock sensor — fitted and worth knowing about

Yes, the 2008 Nissan Serena (C25 series) is fitted with a knock sensor. Nissan’s Electronic Service Manual for the C25 (EC – Engine Control) details the knock sensor signal being used by the ECM to adjust ignition timing on the MR20DE/QR-series petrol engines, and the manual documents DTCs such as P0325 for the knock sensor circuit. Nissan’s FAST electronic parts catalogue also lists a knock sensor for the C25 under the 22060 part code family. Aftermarket catalogues for MR20DE-equipped Serena models further confirm availability of direct-fit knock sensors. Those technical references make it clear the Serena uses a knock sensor as part of its factory engine management.

On a 2008 Serena, the knock sensor is a small, rugged microphone bolted to the engine block beneath the intake side. Its job is to “listen” for abnormal combustion (detonation/knock). When it detects that sharp vibration signature, it signals the ECM, which then trims ignition timing to protect the engine. That keeps the Serena smooth on 91–95 RON fuel, helps fuel economy, and prevents long-term internal damage from persistent pinging.

It’s not a regular service item, but it’s smart to consider the knock sensor during scheduled maintenance. If owners notice rattly pinging under load, a Check Engine light with codes like P0325, sluggish performance, or poorer fuel economy, the knock sensor circuit deserves attention. On this model the sensor sits under the intake, so access can be cramped. Before replacement, a good tech will confirm wiring integrity and connector condition, as brittle looms and poor grounds can mimic a failed sensor.

When replacement is required, using a quality OEM-equivalent sensor matters, and torqueing it to the spec in the Nissan ESM is critical so it reads vibration correctly. While in there, it’s a great time to check for oil weeps on the block face, tidy loom routing, and ensure the intake manifold gaskets reseal nicely if they were disturbed. After fitting, clear codes and perform a road test so the ECM can relearn and verify no further knock activity.

Owners keen to avoid drama can also keep to decent fuel, ensure the cooling system is healthy, and stay on top of spark plug intervals. All of that reduces the conditions that trigger knock in the first place, letting the Serena run happily without the ECM constantly pulling timing.

• Common signs of trouble: Check Engine light (P0325), pinging under load, flat spots, and higher fuel use.
• Best practice: verify wiring first, fit a reputable sensor, and tighten to the factory torque.

FAQs

Where is the knock sensor on a 2008 Nissan Serena?
It’s mounted on the engine block beneath the intake manifold side. On MR20DE models, access is typically from above with intake components moved aside, or from underneath depending on workshop setup. A mirror and good lighting help to spot the single-bolt sensor and its short harness tail.

What fault codes point to a bad knock sensor on a Serena C25?
DTC P0325 is the usual knock sensor circuit code noted in the Nissan ESM. Intermittent wiring or connector issues can set the same code, so testing continuity and inspection for corrosion is part of a proper diagnosis before replacing the sensor.

Can it be driven with a failed knock sensor?
Generally the ECM will pull timing to play it safe, so the van may feel down on power and use a bit more fuel. It’s usually fine to drive short-term, but it’s best to repair promptly—without accurate knock feedback, the ECM can’t optimise ignition timing, and sustained detonation risk increases if other conditions line up.