Parts for your 2003 Nissan Primera-Camshaft sensor

2003 Nissan Primera camshaft sensor — does it have one and what to know

Yes — the 2003 Nissan Primera (P12 series) is fitted with a camshaft position sensor (CMP). This is documented in the Nissan Primera P12 factory service manual (Engine Control / EC section), which details CMP-related diagnostics and wiring. Industry repair databases such as Autodata, and workshop references like Haynes for contemporary Nissan petrol and diesel engines, also specify a CMP on the QG18DE, QR20DE and YD22DDTi engines used in this model year. Nissan’s early‑2000s service campaigns in Europe likewise reference cam and crank sensors on Primera P12 vehicles, reinforcing that the part is an OEM‑fitted, engine‑critical sensor.

On this Primera, the camshaft sensor tells the engine control module exactly where the cam is in its rotation so it can time fuel injection and ignition bang‑on. That’s how the car nails clean starts, smooth idle and decent fuel economy. A crook CMP can cause hard starting, random stalling, misfires, sluggish performance, and the MIL/engine light with fault codes such as P0340 or P0345. Because these Nissans also rely on the crank sensor for synchronisation, many techs check or replace both at the same time when chasing intermittent stalling or no‑start issues.

As part of routine servicing, the sensor itself isn’t a “service item”, but a quick visual once‑over pays off: look for oil wicking into the connector, brittle wiring near the rocker cover, or damage from past work. If the engine’s throwing CMP codes, rule out timing chain stretch or poor grounds before ordering parts.

Replacement is straightforward and usually sits in the “DIY‑able” camp:

• Confirm codes and live data (cam/crank sync) with a scan tool.
• Find the CMP on the cylinder head near the timing chain cover (some QR engines have two, check the engine code/VIN).
• Disconnect the plug, remove the single retaining bolt (typically 10 mm head), ease the sensor out, and swap the O‑ring.
• Lightly oil the new O‑ring, seat the sensor, and torque the bolt to about 8 N·m.
• Clear codes, start the car, and road‑test while watching for stable cam/crank correlation.

For reliability, go with a quality OEM‑equivalent sensor (Nissan/Hitachi). If the Primera has been stalling at idle or when hot, replacing both cam and crank sensors together can save a repeat visit. Owners who keep the electrics tidy and sort any oil leaks around the head usually enjoy heaps of trouble‑free kilometres from the CMP.

Popular questions

Where is the camshaft sensor on a 2003 Nissan Primera?
On most 2003 Primera engines it’s mounted on the cylinder head by the timing chain cover. The QG18DE typically has one sensor on the head, while some QR20DE variants can have two (intake and exhaust sides). It’s held by a single small bolt with an O‑ring seal and an electrical plug.

What are common signs the camshaft sensor is failing?
Hard starts, rough idle, sudden stalling, flat spots under load, and a Check Engine light are common. Diagnostic trouble codes like P0340/P0345 often appear. Because the crank sensor can cause similar grief on these Nissans, smart diagnostics look at both signals together.

Should both cam and crank sensors be replaced at the same time?
Not always, but many techs recommend it on early‑2000s Nissans when there’s a history of hot‑stall or intermittent no‑start. If one has failed and the other shows marginal data or age‑related issues, replacing both can improve long‑term reliability and reduce labour doubling‑up.