Parts for your 2009 Mitsubishi Lancer-Crank angle sensor

2009 Mitsubishi Lancer Crank Angle Sensor

Technical sources confirm that a crank angle sensor (commonly called the crankshaft position sensor, or CKP) is fitted to the 2009 Mitsubishi Lancer across its 4B1-series petrol engines (including 4B11/4B12 and 4B11T). Mitsubishi Motors’ Lancer Service Manual for the CY/CZ series (Engine Group 11A/11C: Engine Control, Sensor Locations and DTCs), along with Haynes Mitsubishi Lancer 2007–2017 and professional databases such as Autodata and ALLDATA, all identify the CKP as a primary engine management input on these models. So yes—it’s relevant and used, and it’s essential for proper starting, fuel delivery, ignition timing and overall drivability.

On the 2009 Lancer, the crank angle sensor reads a toothed target on the crankshaft to tell the ECU exactly where the pistons are and how fast the engine’s spinning. That lets the ECU fire the injectors and coils right on cue, keep idle stable and trim fuel under all sorts of Aussie and Kiwi driving conditions. If the signal drops out or the pattern is wrong, the ECU can’t confidently schedule spark and fuel, which is why a flaky sensor can cause hard starting, stalling, or a no-start. Typical fault codes you’ll see are P0335–P0339, often paired with rough running or the tacho behaving oddly.

This isn’t a routine replacement item, but it’s smart to check it when servicing—especially if there’s oil weeping near the sensor or the wiring looks tired. The sensor on 4B1 engines is mounted to the block near the crank pulley/timing side (some variants sit closer to the bellhousing). Replacement is straightforward: disconnect the battery, pop the bonnet, unplug the connector, remove the retaining bolt, and ease out the sensor without levering against the housing. Lightly oil the O-ring on the new unit, seat it square, and torque the bolt to spec (around 10 N·m—verify for your exact engine). Clear codes, perform an idle relearn if needed, and road-test. Tips:

• Use OEM-quality parts, cheap sensors can cause intermittent faults.
• Inspect the harness for chafe near brackets and the A/C compressor.
• The air gap isn’t adjustable on these engines—fit and torque is key.
• If diagnosing, a scope trace beats a multimeter on Hall-effect CKPs.

Common symptoms that point to a crank angle sensor drama include:

• Cranks but won’t start, especially when hot.
• Intermittent stall at idle or while coasting.
• Sudden loss of power with the MIL on (P0335–P0339).
• Long crank time and poor fuel economy.

FAQs

Where is the crank angle sensor on a 2009 Mitsubishi Lancer?
On most 4B11/4B12 engines it’s mounted to the lower timing side of the block, reading a toothed wheel on the crank. Some variants place it near the bellhousing. From under the car, look just behind the crank pulley area for a small 3‑pin sensor held by a single bolt.

Do I need to program or relearn anything after replacing it?
No special coding is usually required. Clear any stored DTCs, then perform an idle relearn if the idle speed is unstable. The ECU will adapt to the clean signal on its own once you drive and bring it up to temperature.

What are the usual fault codes for a bad crank angle sensor?
The common ones are P0335 (Crankshaft Position Sensor “A” Circuit) through P0339 (range/performance and signal issues). Intermittent stalling or a no‑start with P0335 is a classic sign the CKP has failed or its wiring/connector is compromised.