Parts for your 2005 Toyota Highlander-Knock sensor

2005 Toyota Highlander (Kluger) Knock Sensor: What it does and when to replace

Referencing Toyota’s own technical material, the 2005 Toyota Highlander (known as Kluger in Australia and New Zealand) is absolutely fitted with knock sensor hardware. The Toyota Repair Manual and Toyota Technical Information System (TIS) wiring diagrams specify a knock sensor input to the ECM for both the 2.4L 2AZ-FE (one sensor on the block) and the 3.3L 3MZ-FE V6 (two sensors in the V of the engine). Toyota’s Electronic Parts Catalogue also lists the knock sensor(s) and sub‑harness for these engines, and common OBD-II references for this model include DTCs P0325 and P0330, confirming the circuits’ presence.

The knock sensor’s job is simple but crucial: it “listens” for pinging (detonation) and lets the ECM trim ignition timing to protect the engine while keeping performance and economy on song. When it’s healthy, it helps the Highlander run smoothly on regular unleaded (91 RON in AU/NZ) even under load or on hot days.

If the sensor or its wiring plays up, owners might notice a check engine light, lacklustre performance, higher fuel use, or a flat feeling on hills. The ECM often pulls timing as a safety net. Symptoms can include:

• Check engine light with codes like P0325, P0330, P0327, or P0328
• Sluggish acceleration and reduced power
• Occasional roughness or poor economy

As part of servicing a 2005 Highlander/ Kluger, the knock sensor isn’t a routine replacement item, but it is worth inspecting connectors and looms any time the intake is off. On the 2.4L, the single sensor sits beneath the intake manifold on the block. On the 3.3L V6, there are two sensors and a sub‑harness tucked under the upper intake in the valley. Because access on the V6 requires intake removal, many technicians recommend replacing both sensors and the sub‑harness together if one has failed, using quality OEM‑spec parts and adhering to factory torque and sealing procedures. That way, the labour isn’t doubled later.

Good fuel quality helps the sensor do its best work. Stick with the recommended 91 RON, avoid prolonged driving with active knock-sensor faults, and have a technician verify the issue—genuine knock, a tired sensor, or cracked wiring can present similarly. Once repaired, clearing codes and a proper road test under load will confirm the ECM is happily back to fine‑tuning timing.

• Where is the knock sensor on a 2005 Highlander?
  On the 2.4L 2AZ‑FE there’s one sensor mounted on the engine block below the intake manifold. On the 3.3L 3MZ‑FE V6 there are two sensors in the valley under the intake, connected by a small sub‑harness. Access on the V6 requires removing the intake assembly, so planning parts and gaskets ahead of time saves hassle.
• Is it safe to drive with a bad knock sensor?
  The vehicle will usually run, but the ECM may retard timing to protect the engine, leaving it down on power and using more fuel. Short trips to a workshop are typically fine, but extended driving with the fault can mask real detonation or other issues. Best to sort it promptly.
• Should both sensors be replaced on the V6?
  When one V6 knock sensor fails, many workshops replace both sensors and the sub‑harness while the intake is off. The added parts cost is modest compared with repeating the labour later, and it helps ensure long‑term reliability.