Parts for your 2017 Mitsubishi Asx-Knock sensor

2017 Mitsubishi ASX knock sensor — what it does and how to look after it

Technical sources confirm the 2017 Mitsubishi ASX is fitted with a knock sensor. The Mitsubishi Motors ASX/RVR/Outlander Sport service manual (MY2015–2019, Engine Electrical – Knock Sensor), the MMC ASA global parts catalogue for GA1W/GA2W models (4B11 2.0L MIVEC), and Mitsubishi OBD-II fault listings (e.g. DTC P0325 Knock Sensor Circuit) all specify a block-mounted knock sensor on this vehicle.

On the 2017 ASX, the knock sensor is a clever little microphone bolted to the engine block. It listens for detonation (that sharp “ping” under load) and lets the ECU trim ignition timing on the fly. That helps the 2.0L MIVEC run smoothly on everyday 91 RON fuel across Aussie and Kiwi conditions, protects the engine when it’s working hard, and keeps power and economy on song.

It’s not a scheduled replacement item, but it deserves attention during regular servicing. A quick visual once-over under the bonnet for harness damage, brittle conduit, or oil contamination around the sensor is time well spent. The sensor relies on a clean, flat mounting face and correct clamping force to “hear” properly, so if it’s been off the car, have it refitted to the factory torque (around 24 N·m for the 4B11 — check the exact spec for your engine code).

If the ASX logs a P0325 fault, shows a check-engine light, feels doughy, or drinks more fuel, a proper diagnosis is the go. Don’t whack the block with a spanner to “test” it — that can damage the sensor. Instead, scan live data for knock counts and timing retard, and inspect wiring before replacing parts. When replacement is needed, a quality OE-equivalent sensor and a new connector pigtail (if the old plug is heat-soaked) will save headaches.

Owners can help the knock system out by using reputable fuel, fixing any intake leaks, and keeping cooling up to scratch so combustion temps don’t get away. The knock sensor will still do its protective job if the petrol or conditions aren’t ideal, but chronic pinging points to an underlying issue (carbon build-up, lean running, or overheating) that should be sorted pronto.

• Common signs: check-engine light (P0325), rattly “ping” on hills, sluggish performance, higher fuel use.
• Basic replacement steps: disconnect battery, access sensor on the block, swap sensor, torque to spec, clear codes, road test.

FAQs

Where is the knock sensor on a 2017 Mitsubishi ASX?
On the 2.0L 4B11 engine, it’s mounted mid-way on the engine block beneath the intake manifold side, roughly on the centreline of the block. Access is usually from the top with intake components moved, or from underneath on a hoist. It has one electrical connector and a single retaining bolt.

When should the knock sensor be replaced?
There’s no fixed kilometre interval. Replace it if diagnostics confirm a faulty sensor (e.g. P0325 with wiring proven good), if it’s physically damaged or oil-soaked, or if it fails testing in the service manual. Otherwise, it’s a monitor-and-maintain item during routine services.

What are the symptoms of a bad knock sensor?
You may see a check-engine light, feel reduced power (the ECU retards timing to protect the engine), notice roughness under load, or higher fuel consumption. Persistent audible pinging despite good fuel and no codes suggests another issue that needs attention.