Parts for your 2018 Mazda 3-Crank angle sensor

2018 Mazda 3 crank-angle-sensor

The 2018 Mazda 3 is fitted with a crank-angle-sensor. Mazda’s own technical information confirms it: the Mazda 3 (BN/BM) Workshop Manual for the SKYACTIV-G engines lists a Crankshaft Position (CKP) sensor—often called a crank-angle-sensor—within the Engine Control System. The Mazda electronic wiring diagrams show the CKP circuit feeding the PCM, and Mazda’s service diagnostics include OBD-II DTCs P0335–P0339 specifically for CKP faults. Mazda’s parts catalogue for 2018 Mazda 3 variants also lists a crankshaft position sensor across the 2.0 and 2.5 SKYACTIV-G engines.

On this model, the crank-angle-sensor monitors crankshaft speed and exact position, letting the ECU (PCM) time fuel injection and spark perfectly. It also works with the cam sensor for synchronisation, supports variable valve timing control, stabilises idle, and helps with misfire detection. If it drops out, the engine may crank longer, stumble, or not start at all.

There’s no scheduled replacement for the CKP, it’s a fit-and-forget item until a fault shows up. That said, a quick look during servicing goes a long way—checking the connector for oil ingress or corrosion, making sure the harness isn’t rubbing through, and confirming the sensor mounting is clean and secure. Common symptoms of a crook crank-angle-sensor include hard starting, intermittent stalling once warm, rough idle, sudden loss of power, a dead tachometer, or the MIL on with codes like P0335/P0336.

• If replacement is needed, use quality OEM-equivalent parts to maintain signal accuracy.
• A scan tool helps confirm fault codes and live RPM signal while cranking.
• Expect roughly 0.5–1.0 hours for most workshops, depending on access.

Typical high-level replacement steps (mechanically minded owners only):

1. Disconnect the battery and raise the vehicle safely on stands.
2. Locate the sensor where it faces the crankshaft’s reluctor wheel (mounted to the engine block). Access is usually from below on these engines.
3. Unplug the connector, remove the retaining bolt, and withdraw the sensor. Swap the O-ring if fitted.
4. Install the new sensor, torque to spec per the workshop manual, reconnect, clear codes, and perform a short drive so the PCM relearns.

If unsure, book it with a trusted technician. A poor-quality sensor or damaged wiring can cause repeat faults, so it pays to get it right the first time.

Popular questions about the 2018 Mazda 3 crank-angle-sensor

Does a 2018 Mazda 3 have a crank-angle-sensor?
Yes. Mazda’s 2018 Mazda 3 SKYACTIV-G engines use a crankshaft position (crank-angle) sensor for ignition and fuel timing. This is documented in the Mazda Workshop Manual, supported by the wiring diagrams and the model’s diagnostic codes (P0335–P0339) for the CKP circuit.

Where is the crank-angle-sensor on a 2018 Mazda 3?
It’s mounted to the engine block facing a toothed reluctor on the crankshaft. On most 2018 Mazda 3s, access is from underneath near the gearbox end of the engine. Exact access can vary slightly by engine and undertray setup.

What are symptoms of a failing crank-angle-sensor, and can it be cleaned instead of replaced?
Look for long cranking, no-start when hot, random stalling, rough idle, or the MIL on with CKP codes. Cleaning the connector and removing debris from the sensor nose can help if contamination is the issue, but internal sensor or wiring faults usually require replacement.