Parts for your 2004 Mitsubishi Lancer-Camshaft sensor

2004 Mitsubishi Lancer camshaft sensor: what it does and how to look after it

Yes, the 2004 Mitsubishi Lancer uses a camshaft position sensor. Technical references that cover the CH/CS Lancer platform — including the Mitsubishi Motors Service Manual (Engine Electrical, Group 13A) and the Mitsubishi ASA/CAPS parts catalogue — list a dedicated camshaft sensor for the 2.0L 4G94 and the 2.4L 4G69 engines sold in Australia and New Zealand. The sensor is mounted at the cylinder head to read camshaft phase, and faults typically log as OBD‑II codes such as P0340 or P0341.

On this Lancer, the camshaft sensor’s job is to tell the ECU exactly where the cam is in relation to the crank. That precise timing cues sequential fuel injection, spark timing, quick starts, and stable idle. On 4G69 models with MIVEC, the sensor also helps the ECU manage cam phasing for better torque and efficiency. If the signal goes missing, the ECU may fall back to a rougher, less efficient mode or it may stall and refuse to start.

It’s a solid‑state part, so there’s no routine service interval, but it does benefit from a quick check during scheduled servicing. Under the bonnet, look for oil contamination at the sensor, a brittle connector, or chafed wiring near the timing cover. If engine light warnings appear, scan for codes and confirm live data before ordering parts.

Signs it’s time to replace the sensor can include:

• Hard starting, stalling, or long cranking when warm
• Rough idle, misfires, flat spots, or poor fuel economy
• Check Engine Light with P0340/P0341

Replacement is straightforward for most variants: disconnect the battery, remove any engine cover, unplug the connector, undo the retaining bolt, swap the sensor and O‑ring, then refit and tighten to factory spec. Clear codes, then verify a clean cam signal and stable idle with a scan tool. Labour time is commonly around 0.3–0.6 hours. If faults persist, inspect the crank sensor, timing belt condition/phase, and wiring, as those can mimic cam sensor failures.

For best results, use an OE or reputable aftermarket sensor. A new unit and a tidy harness usually has the Lancer starting first turn and running sweet as again, with no dramas on the daily commute across town or down the motorway.

FAQs

Where is the camshaft sensor on a 2004 Lancer?
It’s typically fitted on the cylinder head at the timing belt end. Access is from above with the engine cover off. The plug points into the engine bay, and a small bolt secures the sensor to the head.

What fault codes point to a bad camshaft sensor?
Common codes are P0340 (Camshaft Position Sensor Circuit) and P0341 (Range/Performance). Always check the wiring and crank sensor signal too, as those can trigger similar codes.

Can they drive with a failing camshaft sensor?
Sometimes the ECU will let it run in a reduced mode, but it may stall, run rough, or be hard to start. It’s safer to sort it promptly to avoid getting stranded and to protect the timing belt and related components from misdiagnosis.