Parts for your 2012 Mitsubishi Lancer-Camshaft sensor

2012 Mitsubishi Lancer Camshaft Sensor — What It Does and When to Replace It

Yes, the 2012 Mitsubishi Lancer uses a camshaft position sensor (CMP). This is confirmed by Mitsubishi’s CJ/CF Lancer workshop manual for the 4B10/4B11/4B12 petrol engines and the Mitsubishi ASA electronic parts catalogue, which list one or two CMP sensors depending on variant, along with related OBD-II fault codes such as P0340, P0341 and P0345. These engines rely on the CMP for sequential fuel injection and MIVEC variable valve timing, so it’s a key bit of kit, not an optional extra.

The camshaft sensor watches the cam’s position and speed, teaming up with the crank sensor to keep spark and fuel timing spot-on. In the Lancer’s MIVEC-equipped engines, the ECU also uses the CMP to control valve timing, helping it start cleanly, pull well through the revs, and sip fuel rather than guzzle it. If the CMP signal goes missing or messy, the car can be hard to start, run rough, drop into limp mode, or throw a check engine light.

There’s no set kilometre-based replacement interval for the CMP on a 2012 Lancer, it’s a replace-on-failure part. That said, a quick look during regular servicing (every 12 months or 15,000 km) is smart. Check the sensor connectors and harness routing under the bonnet for brittle insulation, oil wicking, or loose clips, and keep on top of clean oil and the right viscosity—good oil flow helps the valve timing system behave.

Thinking about replacement? Use an OE or reputable aftermarket sensor matched to your engine code (4B10/4B11/4B12). Most DOHC variants have two sensors—intake and exhaust—so make sure you’re working on the right one. Typical steps are:

• Confirm the fault with a scan tool and live data, note any P0340/P0341/P0345 codes.
• Inspect wiring and connectors first—many “sensor faults” are actually loom issues.
• Remove the engine cover, unplug the connector, and swap the sensor, ensuring the O-ring is seated and the harness is clipped away from heat.
• Clear codes, start the engine, and check for stable cam/crank correlation, perform an idle relearn if required.

If the light comes back, dig deeper: timing chain stretch, contaminated oil, or a sticky VVT solenoid can mimic a bad sensor. A quick, methodical check saves time and keeps the Lancer running sweet as.

Where is the camshaft sensor on a 2012 Mitsubishi Lancer?
On petrol 4B10/4B11/4B12 engines used in 2012 Lancer, the camshaft position sensors sit at the end of the cylinder head near the cam gears—one for the intake and one for the exhaust on most DOHC variants. Pop the bonnet, remove the plastic engine cover and you’ll see the sensors with two-pin connectors at the front/top of the engine.

Do both camshaft sensors need replacing together?
No. Replace only the faulty sensor after confirming the fault with scan data and wiring checks. However, if the vehicle has high kilometres and the pair are original, some owners choose to replace both pre-emptively for peace of mind.

Is it safe to drive with a failing camshaft sensor?
It may start and run, but it can stumble, stall or go into limp mode and chew through more fuel. Continued driving risks misfires and potential catalyst damage. Best to sort it promptly.