Parts for your 2011 Mazda Premacy-Camshaft sensor

2011 Mazda Premacy camshaft sensor — what it does and how to look after it

Yes, the 2011 Mazda Premacy (CR series) is fitted with a camshaft position sensor. Technical sources that detail this include the Mazda Workshop Manual for the CR Premacy/Mazda5 (Engine Control System and On‑Board Diagnostics sections, which specify Camshaft Position [CMP] sensor checks and DTCs such as P0340/P0341), Mazda Global Service Support wiring diagrams (showing the three‑wire Hall‑effect CMP sensor to the PCM), and the Mazda Electronic Parts Catalogue for CR models (listing the camshaft position sensor for the LF/L5 petrol and 2.0‑litre diesel engines). It’s a key input for sequential fuel injection, ignition control and Mazda’s S‑VT variable valve timing.

The camshaft sensor’s job is to tell the PCM exactly where the cam is in its rotation, so the ECU can fire the injectors and spark at the right time and phase the S‑VT properly. Paired with the crank sensor, it also helps crisp hot and cold starts and supports features like i‑stop where fitted. When it goes out of spec, the Premacy can fall back to a default strategy that feels doughy or refuses to start cleanly.

Common signs it’s unhappy include:

• Long crank, rough idle, flat spots or misfire
• Stalling at low speed and poor fuel economy
• Check engine light with codes like P0340/P0341

There’s no scheduled replacement interval, but it’s smart to give it a look during routine servicing. Under the bonnet, the CMP sensor sits on the cylinder head at the timing chain end, with a three‑pin connector. Check for oil weeping past the O‑ring, brittle wiring, or a loose plug. Keeping the area clean and the harness properly clipped pays off over the kilometres.

When replacement’s on the cards, use a quality OEM or reputable aftermarket sensor. With the ignition off and battery negative disconnected, unplug the connector, remove the single retaining bolt, swap the O‑ring if supplied (lightly oil it), and refit the new sensor. Tighten the small bolt snugly (refer to the Mazda workshop manual for the exact torque), reconnect, clear fault codes, then warm the engine and let it idle a few minutes before a short test drive. No special programming is typically required. If a new sensor doesn’t sort the fault, check for timing chain wear, a sticky VVT actuator, poor battery voltage during cranking, or wiring issues between the sensor and PCM.

Tech tip: before condemning the sensor, scope or scan the live CMP/CKP signals if possible, intermittent wiring faults near the upper timing cover are not uncommon on high‑kilometre cars.

FAQ

Where is the camshaft sensor on a 2011 Mazda Premacy?
It’s mounted on the cylinder head at the timing chain end, near the upper timing cover, and has a three‑pin electrical connector. Access is from the top under the bonnet, usually held in by a single small bolt and sealed with an O‑ring.

Does a new camshaft sensor need programming?
No special coding is normally required. After installation, clear the fault codes, start the engine, let it idle to stabilise, and take a short drive. The PCM will use the new signal straight away, i‑stop models may need a brief drive for all readiness monitors to settle.

What usually causes P0340/P0341 on these?
Often it’s a failing sensor, oil contamination at the connector, or damaged wiring/harness clips near the timing cover. Less commonly, incorrect cam timing from chain stretch or a mis‑timed repair can set the same codes. Low battery voltage during cranking can also trigger intermittent CMP faults.