Parts for your 2004 Mazda 6-Crank angle sensor

2004 Mazda 6 Crank Angle Sensor (Crankshaft Position Sensor)

Yes, the 2004 Mazda 6 is fitted with a crank angle sensor, more commonly listed in manuals as the crankshaft position (CKP) sensor. This is confirmed by Mazda’s factory workshop information for the GG/GY Mazda6 (2003–2005) which details CKP sensor diagnostics and replacement for the 2.0L LF, 2.3L L3, and 3.0L AJ V6 engines, as well as OEM parts catalogues that list the CKP sensor for all these engines. It’s a core part of the engine management system, not an optional extra.

The crank angle sensor keeps the Mazda 6’s ECU in the loop about where the crankshaft is and how fast it’s spinning. Using a toothed wheel on the crank, the sensor feeds precise timing signals so the ECU can fire the spark and inject fuel at exactly the right moment. It also helps with things like variable valve timing strategy and smooth idle behaviour. If that signal drops out, the engine can stall, refuse to start, or run roughly.

There’s no scheduled maintenance for the sensor itself, but it’s smart to give it some attention during regular servicing. On the 2.0L/2.3L four-cylinder, the sensor lives near the crank pulley at the front of the engine, on the 3.0L V6 it’s mounted at the rear of the engine reading the flywheel. Checking the wiring loom and connector for heat damage or oil contamination goes a long way to preventing headaches, especially if there are front crank seal weeps on the four-cylinder.

• Common symptoms of a crook CKP: hard starting or no start, random stalling (particularly when hot), uneven idle, misfires, tachometer dropouts, and engine light with codes like P0335–P0339.
• Good servicing habits: keep the connector clean and clipped firmly, route the loom clear of belts and hot exhaust, and fix oil leaks that can foul the sensor or tone wheel.

When replacement is needed, use a quality OEM or reputable aftermarket sensor. Disconnect the battery, verify fault codes, and don’t force the sensor into a dirty bore—clean the mounting area and lightly lubricate the O-ring if fitted. Seat it squarely, tighten the retaining bolt to the factory torque spec (refer to the Mazda workshop manual), and clip the harness as per original. Most Mazda 6s won’t need a special relearn after a CKP swap, but clearing codes and doing a proper road test is good practice.

If the car has racked up big kilometres and shows intermittent CKP-related faults, a pre-emptive replacement can be worthwhile, as an outright failure will leave it stranded.

Popular questions

Where is the crank angle sensor on a 2004 Mazda 6?
On the 2.0L and 2.3L four-cylinder engines, it’s down by the crank pulley at the front of the engine. On the 3.0L V6, it’s at the rear of the engine, reading the flywheel near the transmission bellhousing. Access varies—expect tighter space on the V6.

What are the signs the crank angle sensor is failing?
Classic signs are intermittent no-start, hot stalls, rough idle, misfires, and a dead tach when cranking. The check engine light often tags codes like P0335. If it starts fine cold but plays up hot, the sensor may be breaking down with heat.

Can the Mazda 6 run without the crank angle sensor?
No. If the CKP signal drops out completely, the ECU can’t time spark or fuel, so it won’t run. If the signal is flaky, it may start and then stall or cut out randomly—best not to drive it until the fault is sorted.