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Parts for your 2004 Mitsubishi Lancer-Crank angle sensor
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2004 Mitsubishi Lancer crank angle sensor (CKP): purpose, servicing and replacement
Based on technical references including the Mitsubishi Lancer (CH, 2003–2007) Service Manual (Group 13A – Engine Electrical), the Mitsubishi ASA parts catalogue (listing CKP sensors such as MD327107/1865A066 for 4G9-series engines), and diagnostic data from Autodata/AllDataDIY for OBD-II codes P0335–P0339, the 2004 Mitsubishi Lancer is fitted with a crank angle sensor (also called a crankshaft position sensor or CKP). It’s a required input for the engine control unit on both SOHC 4G94 models and performance variants like the 4G63T Evo of the era.
On a 2004 Lancer, the crank angle sensor keeps tabs on the crankshaft’s speed and exact position. The ECU uses this signal to trigger spark and time fuel injection, handle idle stability, and monitor for misfires. Without a clean CKP signal, the engine can be hard to start, run rough, or cut out unexpectedly.
Depending on engine variant, the sensor is typically mounted at the front of the block reading a toothed wheel on the crank (often behind the lower timing cover near the crank pulley). Some versions place it by the bellhousing to read the flywheel. It’s a solid-state unit, sealed against oil and road grime, and generally maintenance-free.
- Common symptoms: long crank/no start, random stalling, erratic tachometer, reduced power, and OBD-II faults P0335–P0339.
- Good times to inspect: during timing belt service intervals (around 100,000 km or as per the logbook), or whenever chasing misfires or hot-start dramas.
While the sensor isn’t a scheduled replacement item, it’s smart to check the wiring, connector clips and routing under the bonnet for heat damage or oil contamination. Oil leaks around the crank seal can wick into connectors—sort the leak and clean the plug to keep signals crisp.
- If replacement’s on the cards, disconnect the battery, safely raise the front, remove the RH wheel and splash guard, and access the lower timing cover. Take care around the timing belt—this engine family is interference, so no slip-ups.
- Unplug the sensor, remove its retaining bolt(s), and note the harness routing. Fit the new CKP with a fresh O-ring if applicable. Most CKPs have a fixed air gap, if yours is adjustable, set it to the workshop spec.
- Torque the fasteners to the manual’s spec, clip the loom away from hot or moving parts, clear any fault codes, and perform an idle relearn if required.
For reliability, go with a quality OEM or reputable aftermarket sensor. A quick scan-tool check of live CKP rpm during cranking is a handy way to confirm the fix.
Popular questions
Where is the crank angle sensor on a 2004 Lancer?
On most 4G9 engines it’s at the front of the engine, reading the crank trigger wheel behind the lower timing cover near the crank pulley. Some variants read off the flywheel at the bellhousing. If access is tight, removing the RH wheel and inner guard makes life easier.
What are the signs of a failing crank angle sensor on a 2004 Lancer?
Typical signs include intermittent stalling, long crank/no start (especially when hot), rough running, and the rev counter dropping to zero suddenly. Scan tools often show codes like P0335. Heat-soaked sensors can test fine cold and fail when the engine’s warm.
Can a bad crank angle sensor cause no spark?
Yes. The ECU relies on the CKP to fire the coils. If the signal’s missing or erratic, you’ll often get no spark and no injector pulse. Checking for rpm on a scan tool during cranking is a quick way to confirm whether the CKP is talking to the ECU.
