Parts for your 2004 Toyota Echo|yaris-Camshaft sensor

2004 Toyota Echo/Yaris Camshaft Position Sensor

Based on Toyota technical literature—Toyota Global Techinfo (TIS) service manual for the 1NZ‑FE/2NZ‑FE engines, the 2004 Echo/Yaris Electrical Wiring Diagram (EWD), and the factory diagnostics for DTCs P0340/P0341—the 2004 Toyota Echo/Yaris is fitted with a Camshaft Position Sensor (CMP), identified in Toyota docs as “G2”. It’s an essential input to the engine control module (ECM), so it’s definitely relevant on this model.

On a 2004 Echo/Yaris, the camshaft sensor’s job is to tell the ECM exactly where the intake cam is in its rotation. That lets the engine fire the injectors sequentially, keep VVT‑i phasing spot‑on, and cross‑check crank timing for clean starts and smooth running. Under the bonnet, it lives on the cylinder head at the timing chain end (intake side), right near the VVT‑i oil control valve.

When the sensor starts playing up, drivers often notice longer cranking, a bit of a rough idle, the odd stall at lights, lacklustre power, or worse fuel economy. The check engine light with codes like P0340 or P0341 is a classic giveaway. Because it’s a Hall‑effect sensor, it’s not really a periodic service item—think “inspect and replace as needed” rather than scheduled replacement.

Good servicing practice on these cars is simple:

• Keep engine oil fresh and at the right level—VVT‑i and the cam signal both love clean oil.
• Inspect the sensor connector and loom near the timing cover, heat and oil mist can make the plug brittle or the wiring green and crusty.
• If chasing a fault, confirm power, ground, and signal with a scope or a quality scan tool before buying parts.

Replacement is a straightforward DIY for a confident home mechanic:

1. Let the engine cool and disconnect the battery negative.
2. Unplug the CMP connector, remove the single 10 mm retaining bolt, and twist the sensor out.
3. Swap the O‑ring (lightly oil it), seat the new sensor, and nip the bolt to about 9 N·m.
4. Reconnect, clear codes, and take it for a decent drive to let the ECM relearn.

Genuine or high‑quality aftermarket sensors tend to give the best long‑term results. If the car still cranks long after replacement, check the crank sensor, timing chain stretch, or oil control valve function, as those can mimic cam sensor dramas.

Popular questions

Where is the camshaft sensor on a 2004 Toyota Echo/Yaris?

It’s mounted on the intake side of the cylinder head at the timing chain end, beside the VVT‑i oil control valve. Look under the plastic engine cover and you’ll see a small sensor with a single 10 mm bolt and a two‑pin plug.

What are the signs of a failing camshaft sensor?

Common signs include long cranking when cold, a lumpy idle, hesitation, random stalling, and the check engine light with codes like P0340/P0341. Fuel economy can dip and it may feel a bit flat when accelerating.

Is it safe to drive with a bad camshaft sensor?

It may still run, but it can stall or lose power at awkward times. Best to sort it promptly to avoid being stranded and to prevent extra stress on the catalytic converter from misfires.