Parts for your 2020 Holden Astra-Crank angle sensor

2020 Holden Astra crank-angle sensor (crankshaft position sensor) — purpose, checks and replacement

Yes, the 2020 Holden Astra is fitted with a crank-angle sensor, more commonly called the crankshaft position (CKP) sensor. This is confirmed by GM Global Service Information for the Astra K/BK engine controls (which details CKP diagnosis and replacement), GM/ACDelco parts catalogues listing a crankshaft position sensor for the 1.4T and 1.6T engines, and independent workshop data used across Australia and New Zealand. Those technical references show the sensor is integral to ignition and fuel timing on these turbo petrol engines.

On the 2020 Astra, the crank-angle sensor tracks the exact position and speed of the crankshaft and feeds that to the engine control module (ECM). The ECM uses that live signal to time spark and injection, synchronise with the cam sensor, manage boost and idle, and keep emissions in check. If the CKP signal drops out or goes noisy, the Astra can be hard to start, stall at idle, misfire, or refuse to crank-catch altogether. The check engine light usually tags along, often with codes like P0335–P0339.

This isn’t a scheduled service item, but it’s worth a look any time there’s intermittent stalling, extended cranking when hot, or a random misfire that won’t follow a coil or plug. Under the bonnet, the CKP sits at the engine block near the crank, reading a reluctor wheel. Heat, oil contamination, or a chafed harness near the turbo/downpipe can upset the signal.

Replacement is straightforward for a trained tech: disconnect the battery, unplug the sensor, remove the retaining bolt, and swap in a quality unit with a fresh O-ring. Lightly oil the O-ring, keep the tip clean, and route the loom away from hot or moving bits. After installation, clearing fault codes and performing a CKP variation relearn with a scan tool is recommended on these GM powertrains so the ECM can precisely align timing again. Skipping the relearn can leave a slight stumble or false misfire detection under load.

For owners, the best maintenance is preventative: fix any oil weeps that could wick onto the sensor, keep engine grounds tidy, and address heat shielding that’s come loose. If the Astra shows CKP-related faults, using genuine or OEM-equivalent parts and following the relearn procedure will save headaches and keep the turbo four running sweet.

• Technical basis used: GM Global Service Information (Engine Controls – Crankshaft Position Sensor procedures), GM/ACDelco Electronic Parts Catalogue for BK Astra 1.4T/1.6T, and standard workshop diagnostic references applicable to Opel/GM Astra K engines.

FAQ

Does a failing crank-angle sensor stop a 2020 Astra from starting?
Often, yes. If the ECM can’t see a stable crank signal, it won’t trigger spark or fuel. Some units fail only when hot, so the car may start cold and then stall or refuse to restart after a short stop. Scanning for P0335-type codes will usually point in the right direction.

Is the crank-angle sensor a regular service item on the Astra?
No. It’s replaced on condition. During servicing, a good shop will inspect for oil leaks onto the sensor, damaged wiring, or heat damage. If symptoms or fault codes appear, test the sensor and harness before replacing.

Can a DIYer replace the Astra’s crank-angle sensor at home?
It’s doable with the right tools and access, but two things trip people up: sensor access around the turbo area and the required crank variation relearn after fitting. If you don’t have a scan tool that can run the relearn, consider a mobile tech or workshop to finish the job.