Parts for your 2019 Mitsubishi Asx-Knock sensor

2019 Mitsubishi ASX Knock Sensor—What It Does and When To Sort It

Based on technical sources, the 2019 Mitsubishi ASX is fitted with a knock sensor. The Mitsubishi Motors ASX/RVR/Outlander Sport service manual for 4B11 MIVEC petrol engines lists a “Knock Sensor (KS)” as an engine control input and details diagnostics such as DTC P0325/P0330. The Mitsubishi ASA electronic parts catalogue for the GA2W platform also shows a block-mounted “detonation/knocking sensor” for the 2.0L engine. Independent workshop data (commonly used across AU/NZ) likewise includes knock sensor testing procedures for the 2019 ASX.

On the 2019 ASX, the knock sensor’s job is simple but crucial: it listens for pinging (detonation) and tells the engine computer to trim ignition timing so the motor runs smoothly and safely on local fuels. That helps protect the engine from damage, improves driveability, and can save a bit of fuel by letting the ECU run as much timing advance as conditions allow without risking knock.

It’s a robust, sealed piezo sensor bolted to the engine block under the intake side. It isn’t a routine “replace every X kilometres” item, but it does benefit from sensible checks during servicing:

• Give the wiring and connector a quick look for heat damage, oil saturation, or brittle insulation.
• If there are detonation-related fault codes (e.g., P0325) or the ASX feels flat and the MIL is on, test the sensor circuit before throwing parts at it.
• If replacement is needed, use a genuine or high-quality OEM sensor. Install on a clean, dry mating surface—no thread sealant—and torque to spec (around 24 N·m, confirm in the workshop manual for your VIN).

Signs the knock sensor or its circuit needs attention include a check engine light, noticeably reduced power (the ECU pulls timing as a safeguard), poor fuel economy, or persistent pinging under load. Don’t ignore a persistent knock, while the ECU will try to protect the engine, ongoing detonation can be harmful.

Most owners will never touch the sensor, but it’s worth asking a tech to inspect the harness and check for stored codes at major services or if the ASX is used in hot, high-load conditions. Keeping the cooling system healthy and running the recommended octane petrol also helps the sensor do its best work—less knock detected means the ECU can keep performance crisp and consistent.

Popular questions

Where is the knock sensor on a 2019 Mitsubishi ASX?
It’s mounted on the engine block beneath the intake manifold area. Access usually requires working from above with the intake ducting removed, or from underneath, depending on tools and workshop setup.

Can the ASX be driven with a bad knock sensor?
It will usually run, but performance often drops as the ECU dials back timing. Prolonged driving with a faulty sensor isn’t recommended—have it diagnosed and repaired to avoid potential engine knock risks.

Do knock sensors need regular replacement?
No. They’re not a scheduled service item. Replace only if there’s a confirmed fault, damage, or a relevant DTC after proper testing.