Parts for your 2018 Toyota Crown-Knock sensor

2018 Toyota Crown knock sensor — what it does, when to touch it, and how to keep it happy

Based on technical coverage in Toyota’s Repair Manual for the Crown (S220 series, 2018–, Engine/ECM section “Knock Control Sensor Circuit” with DTCs P0325, P0327, P0328, P0330) and the Toyota Electronic Parts Catalogue listings for the A25A-FXS hybrid, 8AR-FTS 2.0 turbo, and 8GR-FXS V6 hybrid engines, the 2018 Toyota Crown is fitted with knock sensor(s). These are bolted to the engine block and monitored by the ECM to manage ignition timing.

On a 2018 Toyota Crown, the knock sensor is there to listen for knock (detonation) and let the ECU tweak timing so the engine can run smoothly and efficiently without damaging itself. It’s a smart bit of kit that keeps power and fuel economy on point, especially on Aussie and Kiwi 95–98 RON fuels. Depending on engine, there’s one sensor on the block (inline‑four) or two sensors, one per bank (V6), typically tucked under the intake area where they can “hear” block vibration clearly.

It’s not a regular replacement item—think of it like a microphone rather than a filter or fluid. During routine servicing, it’s worth checking the engine harness routing, connector condition, and for any signs of oil/coolant weeping onto the sensor or plug. If the dash lights up with a check engine lamp and the scan tool shows P0325/P0330 variants, that’s the time to test the circuit and sensor properly.

• Common clues it’s unhappy: check engine light, sluggish performance, poor fuel economy, or pinging under load. Sometimes the ECU will pull timing so hard it feels flat as a tack.
• Best prevention: use quality fuel, keep the cooling system healthy, and fix intake or vacuum leaks that can push the tune lean.

If a replacement is needed, it’s straight‑forward but fussy about detail. The sensor relies on correct torque and a clean, flat mating surface to “hear” properly. Don’t paint, grease, or tape the block pad or sensor face. Follow the factory torque spec, use a torque wrench, and route the loom exactly as per the manual so it doesn’t chafe or pick up false noise. Clear codes, perform an ECM learning drive, and make sure no new DTCs return.

1. Disconnect battery and remove intake bits as needed for access.
2. Unplug sensor, remove the old unit, clean the mounting pad.
3. Install new sensor to spec, reconnect, refit intake parts, scan and road test.

FAQs

Where is the knock sensor on a 2018 Toyota Crown?
On the 8AR-FTS and A25A-FXS four‑cylinders it’s mounted on the engine block beneath the intake side, roughly mid‑block. On the 8GR‑FXS V6 there are typically two sensors, one per bank, located in the valley/block area. Access usually means removing some intake hardware under the bonnet.

Does the knock sensor need routine replacement?
No. It’s not a scheduled item. Inspect wiring and connectors during major services (for example around 100,000–120,000 km) and only replace the sensor if diagnostics confirm faults (e.g., DTC P0325/P0330 or out‑of‑range signals).

What symptoms show a bad knock sensor on a Crown?
Expect a check engine light, reduced power from timing being pulled, rough running, or audible pinging. A scan tool will often show the relevant codes and knock correction behaviour. Proper testing beats guesswork before parts are swapped.