Parts for your 2020 Mitsubishi Asx-Knock sensor

2020 Mitsubishi ASX Knock Sensor: What it does and how it fits into servicing

Yes, the 2020 Mitsubishi ASX is fitted with a knock sensor and it’s very relevant to how the engine keeps itself safe and efficient. This is confirmed by Mitsubishi Motors’ workshop manuals for ASX/RVR/Outlander Sport (2019–2020 editions), which include knock sensor inspection and diagnostic procedures, the Mitsubishi ASA electronic parts catalogue for GA/GL series ASX with 4B11 and 4B12 engines, which lists a knock sensor on the cylinder block, and the factory OBD-II DTC listings that include knock sensor fault codes (P0325–P0328) for this model.

On the 2.0L (4B11) and 2.4L (4B12) petrol engines used in the 2020 ASX, the knock sensor is a small, bolt-on piezoelectric microphone mounted to the engine block. Its job is to “listen” for detonation (pinging) and let the ECU trim ignition timing on the fly. That means better protection on hot days, during hard climbs, or when lower-octane fuel finds its way into the tank. With a healthy knock sensor, the ASX can run smoothly on everyday NZ and Aussie petrol without risking piston or bearing damage from uncontrolled knock.

For servicing, the knock sensor isn’t a scheduled replacement item. It’s typically replaced only if diagnosed faulty. Telltales include a check engine light with codes like P0325, noticeable loss of power as the ECU plays it safe with conservative timing, and occasionally rough running. A technician will confirm with the factory test procedure, checking sensor signal, wiring integrity and connector condition.

If replacement is required, it’s a straightforward job for a trained tech: access the sensor on the block (commonly beneath the intake side), disconnect the harness, and refit a genuine-quality sensor to the specified torque, ensuring the mating surface is clean and the harness is routed and clipped correctly. Over-tightening, thread sealants on the sensor face, or leaving oil residue between the sensor and block can spoil signal quality.

Good maintenance habits help: keep an eye out for oil leaks that might soak the sensor, repair any loom chafing early, and use fuel that meets the octane guidance in the owner’s manual. If the dash light pops on with a knock-sensor code, it’s wise to book it in promptly—drivability and fuel use often improve once the fault is fixed, and the engine’s knock protection is restored.

• Common related fault codes: P0325, P0326, P0327, P0328
• Best practice: follow factory torque specs, avoid aftermarket “universal” sensors
• Symptom check: reduced power, higher fuel use, MIL illuminated

FAQs

Does the 2020 Mitsubishi ASX actually have a knock sensor?
It does. Both the 2.0L and 2.4L petrol engines in the 2020 ASX use a block-mounted knock sensor. It feeds the ECU with real-time knock data so timing can be adjusted to protect the engine and maintain performance.

What are the signs the knock sensor on a 2020 ASX might be failing?
Common signs include a check engine light (often P0325–P0328), slightly dulled performance, and poorer fuel economy as the ECU runs safer ignition timing. Physical damage to the sensor or wiring, or contamination between the sensor and block, can trigger these symptoms.

Is it safe to keep driving with a knock sensor fault?
Short trips may be manageable, as the ECU usually dials back timing to protect the engine. But it’s not ideal. The ASX will feel a bit flat and could use more fuel. Getting the fault diagnosed and repaired promptly restores normal performance and ensures proper knock protection.