Parts for your 2022 Toyota Prius-Knock sensor

2022 Toyota Prius knock sensor — what it does and when to sort it

Yes, the 2022 Toyota Prius is fitted with a knock sensor. Technical sources back this up: Toyota’s Repair Manual for the ZVW51/ZVW55 series shows a knock (knock-control) sensor mounted to the 2ZR-FXE engine block and wired to the ECM, the Toyota Electrical Wiring Diagram identifies the KNK/KNKS circuit, and the New Car Features (NCF) manual for the 2ZR-FXE explains knock control for ignition timing. Applicable OBD-II diagnostics include P0325–P0330 for knock sensor circuit/performance.

On this hybrid, the knock sensor listens for high-frequency vibration (spark knock/ping) and lets the ECU trim ignition timing before anything nasty happens. That protects the alloy engine from damage, smooths performance and helps keep fuel use tidy — handy with variable fuel quality across AU and NZ.

It’s not a scheduled service item, but it absolutely plays a long game in engine longevity. During regular servicing, it’s smart to have the tech scan for fault codes, eyeball the sensor harness under the intake side for rub-through or oil contamination, and confirm the connector is clean and snug. Because the Prius can run whisper-quiet on electric assist, drivers may not hear detonation, so the ECU and sensor are your early warning system.

If the sensor or its wiring goes crook, you might see the MIL come on and notice lazier throttle response or higher fuel use as the ECU runs safer timing. Before replacing the sensor, a proper diagnostic is key: verify DTCs (P0325/P0327/P0328), check live knock counts, inspect wiring continuity and grounds, and rule out genuine mechanical noise. Many “sensor” faults end up being a cracked connector, aftermarket intake resonance, or poor engine earth.

Replacement is straightforward for a trained tech: access is typically beneath the intake manifold on the block. The mating surface must be clean metal, no sealants. Fit the correct-spec sensor, route the loom as per the manual, and torque it precisely to Toyota spec — over- or under-tightening can skew readings. Disconnect the 12V battery and observe hybrid safety around any orange HV cabling nearby. Finish with a code clear and a road test under light load to confirm stable knock control.

Day to day, stick with good-quality fuel, keep up with servicing, and let the ECU do its thing. If a light pops up, don’t leave it for kilometres — book it in and save the engine a headache.

• Toyota Repair Manual (RM) – 2022 Prius (ZVW51/55), Engine/Hybrid System: Knock Sensor and DTC P0325–P0330
• Toyota Electrical Wiring Diagram (EWD) – KNK/KNKS circuit to ECM
• Toyota New Car Features (NCF) – 2ZR-FXE ignition timing and knock control

Popular questions

Does the 2022 Prius actually have a knock sensor?
It does. Toyota’s service information for the ZVW51/ZVW55 lists a knock-control sensor on the 2ZR-FXE engine, and the wiring diagram shows the dedicated knock signal to the ECM. Relevant fault codes (P0325–P0330) are defined for this model.

When should the knock sensor be replaced on a 2022 Prius?
There’s no routine interval. Replace it only after proper diagnosis if codes like P0325/P0327/P0328 are present and wiring, grounds, and actual engine noise are ruled out. Many issues trace back to connectors or harness damage, so test before you toss parts.

Is it OK to drive with a faulty knock sensor?
The ECU will usually pull timing to protect the engine, so it’ll run but feel a bit doughy and use more fuel. Short trips to a workshop are typically fine, but ongoing driving isn’t wise — you’re risking performance and, in worst cases, engine health if real knock isn’t being managed.