Parts for your 2021 Honda Cr-v-Knock sensor

2021 Honda CR‑V Knock Sensor: what it does and how to look after it

Technical sources confirm the 2021 Honda CR‑V is fitted with a knock sensor. The Honda CR‑V 2017–2022 Service Manual covers knock sensor (KS) diagnosis and PCM strategy, and the Honda Electronic Parts Catalogue lists “Sensor, Knock” for both the 1.5‑litre turbo petrol (L15B7) and the 2.0‑litre hybrid petrol variants. Honda’s diagnostic coverage also includes DTCs such as P0325 for knock sensor circuit faults on this model. So yes—this is a relevant, factory‑fitted component on the 2021 CR‑V.

On the CR‑V, the knock sensor is a small piezoelectric microphone bolted to the engine block. Its job is to listen for detonation (knock) and let the powertrain control module fine‑tune ignition timing, fuel delivery and—on the turbo—boost, to keep things smooth and protect the engine. It’s one of the quiet achievers that helps the car run happily on everyday Aussie and Kiwi fuels, even when it’s a scorching day, climbing a hill with the family on board.

As for servicing, the knock sensor isn’t a scheduled replacement item. It generally lives a long life unless it’s damaged by heat, vibration, coolant or oil intrusion, or wiring issues. Good workshop practice during regular servicing is simply to keep an eye out for harness rub points, brittle connectors and any signs of leaks under the intake side of the engine. If the check engine light pops up with codes like P0325 and the car feels doughy, uses more fuel, or has rattly pinging under load, a proper diagnosis is in order.

Replacement is straightforward for a trained technician but can be fiddly due to access. Correct torque to Honda spec is important—overtightening can kill a new sensor, while undertightening can make it deaf. A genuine or high‑quality OEM‑equivalent sensor is recommended so the calibration remains spot‑on. After fitting, clearing codes and performing any required idle learn or road test helps the control module relearn knock characteristics.

Owners who keep the cooling system healthy, use quality petrol, and fix intake or vacuum leaks promptly are already doing right by the knock sensor. It’s a small part, but it’s central to keeping the 2021 CR‑V efficient, quiet and reliable over many kilometres.

• Common signs of trouble: check engine light (P0325), reduced performance, higher fuel use, audible ping under load.
• Helpful habits: fix oil/coolant leaks, avoid harsh engine bay washing, and don’t ignore wiring damage.

Popular questions about the 2021 Honda CR‑V knock sensor

Where is the knock sensor on a 2021 CR‑V?
It’s mounted to the engine block, typically beneath the intake side on the 1.5‑litre turbo engine, where it can “hear” combustion events clearly. Access usually involves removing intake ducting and working around the manifold area, so it’s a job best left to a pro if tools and space are limited.

What are the symptoms of a bad knock sensor on a 2021 CR‑V?
The big clue is a check engine light with a knock sensor circuit code (commonly P0325). Drivers might also notice flat performance, higher fuel consumption, or rattly pinging under load because the engine can’t accurately adjust timing. Sometimes it’s the wiring or connector at fault rather than the sensor itself.

Does the knock sensor need regular servicing?
No scheduled service is required. During routine maintenance, a quick visual check for leaks and wiring damage is enough. Replace the sensor only if diagnosed faulty, and have it torqued to Honda spec so it reads knock properly.