Parts for your 2018 Toyota Avensis-Camshaft sensor

2018 Toyota Avensis camshaft sensor — purpose, servicing and handy tips

Yes, the 2018 Toyota Avensis uses a camshaft position sensor (CMP). Technical references including Toyota’s Avensis T27 workshop material and wiring diagrams list the camshaft position sensor (often labelled “G Sensor”) for the 1.6/1.8 Valvematic petrol engines (ZR series) and the 1.6/2.0 D-4D diesels used in this model year. These sources also document related diagnostic trouble codes such as P0340 and P0343 for the CMP circuit, and the Toyota parts catalog lists a dedicated “Sensor, Camshaft Position” for the 2015–2018 Avensis range. So, it’s very much a fitted and functional component on this vehicle.

The camshaft sensor’s job is to tell the engine control module exactly where the camshaft is in its rotation. That timing info lets the ECU fire the injectors in sequence, manage ignition on petrol variants, and control variable valve timing (VVT-i/Valvematic) for smooth power and good fuel economy. On the diesels, it works together with the crank sensor to keep injection precisely synchronised. If the sensor signal goes missing or drifts, you can get hard starting, rough idle, flat spots, or a check engine light — and the car may drop into limp mode to protect itself.

It’s not a routine “wear” item, so there’s no fixed replacement interval. During regular servicing, a quick visual check is worth it: look for oil weeping at the sensor O-ring, damaged wiring, or brittle connectors under the bonnet near the cam cover. Oil quality matters too — correct grade and timely changes help the valve timing system stay clean, which reduces the chance of contamination affecting the sensor reading.

If replacement is needed, it’s a simple job on most Avensis engines:

• Disconnect the battery, unplug the sensor, remove the single retaining bolt.
• Lightly oil the new O-ring, fit the new sensor, and tighten the bolt to the workshop manual spec.
• Clear any fault codes with a scan tool and let the ECU complete an idle learn after start-up.

Quality matters here — go for genuine or a reputable aftermarket part. Typical driveway time is 15–30 minutes with basic tools. If a warning light comes back, check the loom and the crank sensor as they work as a pair. A quick road test over a few kilometres will confirm stable operation and restored performance.

Popular questions

Where is the camshaft sensor on a 2018 Avensis?
On the 1.6/1.8 Valvematic petrol, it’s at the end of the cylinder head by the cam pulley area, accessible from the top. On the diesel variants, it’s similarly mounted at the camshaft end on the head. Look for a small two- or three-pin sensor with a single retaining bolt.

If space is tight, remove the engine cover and a nearby intake duct to get a clean line of sight. A torch and a small ratchet make the job easier.

How often should the camshaft sensor be replaced?
There’s no scheduled interval — it’s replaced on condition. If you see DTCs like P0340/P0343, long cranking, misfires at idle, or poor fuel economy, test the sensor and wiring. If confirmed faulty or oil-soaked, replace it and fit a fresh O-ring.

As part of routine servicing, just inspect the connector and keep an eye out for oil leaks around the cam cover.

Is it safe to drive with a faulty camshaft sensor?
Short trips to a workshop are usually fine, but performance may be reduced and starting can be hit-and-miss. Prolonged driving with a failing signal can stress other components and hurt fuel economy. Best to sort it promptly and clear codes after repair.