Parts for your 2015 Nissan Serena-Knock sensor

2015 Nissan Serena knock sensor — what it does and how to look after it

Yes, the 2015 Nissan Serena (C26 series) is fitted with a knock sensor from factory. Nissan’s C26 Serena Engine Control (EC) technical documentation describes a Knock Sensor (KS) input used for closed‑loop ignition timing control and includes diagnostics for DTC P0325 Knock Sensor Circuit. The C26 Serena service manual’s EC section and Nissan’s parts catalogue for the MR20‑series petrol engines used in the Serena both list a block‑mounted knock sensor.

The knock sensor’s job is to “listen” for detonation (pinging) and let the engine computer trim ignition timing to keep things smooth and protect the motor. On the 2015 Serena’s MR20‑series engine, that means better driveability, safer operation on day‑to‑day 91–95 RON fuel, and fewer dramas when conditions get hot or the vehicle’s under load with the family on board.

It’s not a scheduled replacement item, but it’s smart to give it a bit of attention during servicing. A technician will typically scan for codes (notably P0325), check live knock feedback, and inspect the sensor’s harness and connector for oil soak or brittle insulation under the intake manifold. If the car’s been around the block a few hundred thousand kilometres, a close look at the loom’s routing and earths is worthwhile.

• Common signs of trouble: persistent pinging under load, flat or hesitant performance, worse fuel economy, and a stored P0325.
• Location: usually on the engine block beneath the intake manifold, mid‑block area. Access may need the air ducting or manifold gear moved aside.
• Fuel: always use the octane recommended in the owner’s manual. Poor fuel can provoke knock events the sensor then has to manage.

Replacement, when required, is straightforward for a pro: disconnect the battery, gain access under the bonnet, unplug the connector, swap the sensor, and torque it to the service‑manual spec so it can “hear” correctly. Over‑ or under‑tightening can skew readings. Genuine or high‑quality aftermarket sensors are the go, cheapies can be noisy or deaf. After fitting, clear codes and road‑test to confirm timing control is active and no knock counts are spiking.

If a faulty sensor forces the ECU to play it safe, the Serena will usually run with softened timing so it’s drivable, but power and economy drop. Best not to tow or tackle big hills like that—book it in and get it sorted.

• Does the 2015 Nissan Serena have a knock sensor?
  Yes. The C26 Serena’s MR20‑series petrol engine uses a block‑mounted knock sensor for detonation control, as described in Nissan’s EC (Engine Control) service manual and associated diagnostics for DTC P0325.
• Where is the knock sensor on a 2015 Serena?
  It’s typically mounted on the engine block beneath the intake manifold, about mid‑block. Access varies, many techs remove the intake ducting and work from above, though some prefer access from underneath on a hoist.
• Can a knock sensor be cleaned, or does it need replacing?
  The sensor itself isn’t a serviceable item. If it’s faulty, it’s replaced. During servicing, the connector and wiring can be cleaned and secured, which often prevents intermittent faults.