Parts for your 2005 Toyota Prius-Camshaft sensor

2005 Toyota Prius camshaft sensor: what it is, why it matters, and how to look after it

Technical documentation confirms the 2005 Toyota Prius (NHW20, 1NZ‑FXE) is fitted with a camshaft position sensor. Toyota’s New Car Features guide for the 2004–2009 Prius describes intake VVT‑i control using a camshaft position signal, the Toyota Repair Manual lists DTCs P0340/P0341 specifically for the camshaft position sensor circuit, and the 2005 Prius Electrical Wiring Diagram shows the camshaft position sensor signal routing to the ECM. So yes—this part is relevant and used on this vehicle.

On a 2005 Prius, the camshaft sensor tells the engine control module exactly where the intake cam is, so it can sync fuel injection, manage spark, and correctly target the Prius’s VVT‑i for smooth, efficient running. Without a clean, reliable signal, the hybrid can struggle to start, run roughly when the engine kicks in, and burn more fuel than it should. The dash may light up with a Check Engine lamp and store codes like P0340 or P0341.

It’s a low‑maintenance item—there’s no scheduled replacement—but it pays to keep the area clean and oil‑tight. Under the bonnet, oil leaks from the rocker cover gasket can track down to the sensor and connector, causing contamination or softened seals over time. If there’s an oil weep, fix the leak and clean the connector carefully.

• Common signs of trouble: longer cranking before the engine fires, rough idle when the engine is on, reduced performance, worse fuel economy, and fault codes P0340/P0341.
• Basic replacement tips: disconnect the 12‑V negative terminal, unplug the sensor, remove its single retaining bolt, and withdraw the sensor. Lightly oil the new O‑ring, seat the sensor, and tighten the bolt to about 9–10 N·m. Reconnect and clear codes. Always use a quality part that matches the 1NZ‑FXE.
• Hybrid safety: make sure the car is not in READY, keep the key/fob away, and avoid loose clothing around belts. Disconnecting the 12‑V system prevents the engine from starting itself while you’re working.

If the Prius is throwing a cam sensor code, check the wiring first. Harnesses can chafe near the timing chain end of the head. If the wiring and connector test fine, the sensor itself is a quick swap and not a big job. A good fix restores easy starts, smooth take‑offs, and keeps that 1.5‑litre humming along nicely on trans‑Tasman commutes and city hops alike.

Popular questions

Where is the camshaft sensor on a 2005 Prius?
It’s mounted on the cylinder head at the timing chain end (driver’s side on RHD cars), reading the intake cam sprocket. Look for a small two‑wire sensor secured by a single bolt, with its connector facing up or sideways near the top of the engine.

Can a bad camshaft sensor stop a Prius from starting?
It can cause long cranking or intermittent no‑start when the petrol engine is commanded to run. The hybrid system might still power up, but the engine can stumble, start late, or set P0340/P0341. Fixing the sensor or wiring usually restores normal starts.

Do camshaft sensors need regular servicing?
Not routinely. They’re replace‑on‑failure parts. During services, it’s smart to inspect for oil leaks around the rocker cover, check the sensor connector for contamination, and make sure the harness isn’t rubbed through.