Parts for your 2013 Toyota Prius-Knock sensor

2013 Toyota Prius knock sensor: what it does, where it lives, and when to sort it

Yes, the 2013 Toyota Prius (ZVW30, 2ZR‑FXE) is fitted with a knock sensor. This is documented in Toyota’s Repair Manual for the 2ZR‑FXE engine (Knock Sensor section), the 2013 Prius Electrical Wiring Diagram showing the KNK circuit to the ECM, and the Toyota Electronic Parts Catalogue listing the knock sensor for the 2ZR‑FXE (commonly catalogued as 89615‑12090, confirm by VIN). So, it’s absolutely relevant on this model.

The knock sensor’s job is to “listen” for knock (detonation) in the engine block and feed that info to the engine control module. If the sensor picks up pinging—maybe from hot weather, a heavy right foot up a hill, or a different batch of fuel—the Prius can nudge ignition timing to keep things smooth and protect the engine. Even though the 2ZR‑FXE runs an Atkinson cycle and loves sipping petrol, it still benefits from closed‑loop knock control, especially with E10 fuels common across Australia and New Zealand.

It’s not a normal service item, but it should be on the radar during major services or when chasing drivability issues. Tell‑tales that point to knock sensor trouble include lacklustre performance, worse fuel economy, rattly pinging under load, or the MIL lighting with codes like P0324, P0325, P0327 or P0328. Because false knock signals are often wiring‑related, a careful look at the harness under the intake manifold (heat, oil, or rodent nibbles) can save a lot of grief.

• Access: Mounted to the block beneath the intake manifold, the manifold usually needs to come off.
• Replacement tips: Disconnect the 12‑V battery, keep the sealing faces clean, and torque the sensor correctly—around 20 N·m (15 ft·lbf). Over‑ or under‑torque can skew readings.
• Good practice: Use the correct single‑wire shielded lead, route it as per factory clips, and avoid aftermarket tape blobs that can trap heat and oil.
• When to replace: Only when confirmed faulty by diagnostics (scope trace or resistance/spec checks per Toyota manual), or if the connector/housing is damaged.

Owners doing big kilometres, lots of urban stop‑start, or towing small loads up steep grades may notice the Prius leaning more on knock control—another reason to keep the sensor and its wiring healthy. Technical sources: Toyota Repair Manual (2013 Prius, Engine/2ZR‑FXE, Knock Sensor), Toyota Electrical Wiring Diagram (2013 Prius KNK circuit), and Toyota EPC for 2ZR‑FXE knock sensor part listing.

• Where is the knock sensor on a 2013 Prius and how tough is the job?
  It’s bolted to the engine block under the intake manifold on the 2ZR‑FXE. The manifold generally has to come off, so it’s a bit more involved than a driveway spark‑plug swap. A competent home mechanic with the right tools, patience, and the torque spec can handle it, but many owners prefer a workshop due to the manifold and wiring access.
• What fault codes point to a crook knock sensor?
  Common Prius codes are P0324 (knock control system error), P0325 (knock sensor circuit), P0327 (low input), and P0328 (high input). Before throwing parts, check the loom, connector, and torque, poor contact or shielding often mimics a failed sensor.
• Is it safe to keep driving with a knock sensor fault?
  The car will usually default to conservative timing, so it may feel down on power and sip a bit more fuel. Occasional short trips are unlikely to cook the engine, but prolonged driving while the ECM can’t detect knock isn’t wise. Sorting it sooner protects the engine and restores proper performance.