Parts for your 2004 Toyota Highlander-Camshaft sensor

2004 Toyota Highlander Camshaft Sensor: What It Does and When to Replace It

Yes, a camshaft sensor is fitted to the 2004 Toyota Highlander. Toyota’s technical documentation confirms it: the 2004 Repair Manual and Electrical Wiring Diagram (via Toyota Technical Information System, TIS) list a Camshaft Position Sensor for both Highlander engines. The 2.4L 2AZ‑FE uses one sensor, while the 3.3L 3MZ‑FE V6 uses two (one per bank). The manuals also include diagnostic routines for DTCs P0340 (Camshaft Position Sensor “A” Circuit) and P0345 (Camshaft Position Sensor “B”/Bank 2), which only apply if a cam sensor is present.

On this Highlander, the camshaft sensor lets the engine control module know exactly where the cam(s) are in relation to the crank. That timing info is crucial for clean starts, precise fuel injection, stable idle, and letting VVT‑i do its thing for power and economy. When the sensor goes out of whack, drivers may see a check engine light, hard starting, rough running, misfires, poor fuel use, or the trans holding gears oddly.

It’s not a scheduled service item, but it’s smart to check it during routine servicing—especially on higher‑kilometre vehicles. Look for oil seepage at the sensor O‑ring, brittle wiring near the plug, or green corrosion in the connector. Keeping engine oil fresh and the correct grade helps, because sludgy oil can upset cam timing behaviour and, indirectly, the sensor signal quality.

If replacement is needed, it’s a straightforward DIY for many. Under the bonnet, remove the engine cover. On the 2.4L, the sensor sits on the cylinder head at the timing chain end. On the 3.3L V6, there’s one on each cylinder head. Disconnect the battery, unplug the connector, remove the small retaining bolt, and ease out the sensor. Lightly oil the new O‑ring, seat the new unit, and torque the bolt to about 8–10 N·m. Clear codes and road‑test. Using a quality OEM‑equivalent (often Denso for Toyota) helps avoid comeback issues.

• Common fault codes: P0340 (Bank 1), P0345 (Bank 2 on V6).
• Check harness routing, repair chafed or oil‑soaked wiring.
• If the V6 logs cam codes, also inspect the crank sensor and VVT‑i oil control valves.

FAQ

Where is the camshaft sensor on a 2004 Highlander?
On the 2.4L 2AZ‑FE, it’s mounted on the cylinder head at the timing chain end under the engine cover. On the 3.3L 3MZ‑FE V6, there are two—one on each cylinder head. Each is held by a single small bolt with an O‑ring seal and has a two‑ or three‑pin connector.

Can a camshaft sensor be cleaned, or should it be replaced?
If it’s just oily, a quick wipe and a fresh O‑ring can help. But if the internal Hall‑effect electronics are failing, cleaning won’t revive it—replacement is the go. Always rule out wiring or connector issues before fitting a new sensor.

Do both cam sensors need replacing on the V6?
No. Replace the one that’s faulty, guided by the code and live‑data testing. If both are the same age and kilometres, some techs proactively replace them as a pair, but it’s not mandatory. Check related items like the crank sensor and VVT‑i oil control valves if symptoms persist.