Parts for your 2018 Holden Astra-Crank angle sensor

2018 Holden Astra crank-angle sensor (crankshaft position sensor)

Yes, the 2018 Holden Astra (BK, Astra K) is fitted with a crank-angle sensor, more commonly called a crankshaft position (CKP) sensor. This is documented in GM/Opel Service Information (Astra K, Engine Controls – Crankshaft Position Sensor Description and Operation), confirmed in the Holden Electronic Parts Catalogue for the BK Astra (which lists a CKP sensor across the 1.4T and 1.6T engines), and mirrored by ACDelco and Bosch replacement parts catalogues that specify direct-fit CKP sensors for 2018 Astra variants.

The CKP sensor’s job is to tell the engine control module exactly where the crankshaft is and how fast it’s spinning. Using a toothed reluctor on the crank, the sensor feeds precise timing data for spark and fuel injection, keeps the tacho honest, and enables quick starts and smooth running. If it goes out to lunch, the Astra can be hard to start, stall, misfire, drop the rev counter to zero, or throw lights with codes like P0335/P0336.

It’s not a scheduled service item, but it deserves some attention during routine servicing. Under the bonnet, check the sensor’s wiring and connector for chafe, oil contamination, or water ingress. Oil leaks can wick down the harness and upset the signal, so fixing seepage around the timing cover or rear main area can save headaches. Avoid blasting the connector with a pressure washer.

Replacement is straightforward for a competent technician: disconnect the battery, safely raise the car if needed, locate the sensor on the engine block near the transmission bellhousing area, unplug the connector, remove the single retaining bolt, and withdraw the sensor. Lightly lube the new O-ring, install the new unit, route the harness as per factory, and tighten the retaining bolt to the manufacturer’s spec (typically around 8–10 Nm for an M6 fastener, but always verify in GM SI). After refit, clear fault codes and, where applicable, carry out a CKP variation learn with a suitable scan tool to calibrate misfire detection and timing adaptation—GM SI notes this procedure under Engine Controls. Genuine or quality OE-equivalent parts are recommended to maintain a clean signal and proper shielding.

A well-sorted CKP sensor keeps the Astra crisp on cold starts, maintains good fuel economy, and helps the ECM keep timing spot-on—small part, big impact.

• Common signs: no-start or long crank, random stalls, erratic tacho, limp mode, P0335/P0336.
• Good practice: inspect loom and connector each service, keep oil and water away from the plug, perform relearn after replacement if specified.

Popular questions about the 2018 Holden Astra crank-angle sensor

Where is the crank-angle sensor on a 2018 Holden Astra?
On most BK Astra 1.4T and 1.6T engines, the CKP sensor is mounted low on the engine block near the transmission bellhousing, reading a reluctor on the crank. Access is usually from underneath, a torch helps to spot the single-bolt flange and the two-pin (or three-pin) connector.

What are the symptoms of a failing crank-angle sensor on an Astra BK?
Typical symptoms include long crank or a no-start when hot, intermittent stalling, misfires, a dead or jumpy rev counter, and the MIL on with faults like P0335 or P0336. If the signal drops out, the engine can shut down because the ECM loses timing reference.

Do I need a relearn after replacing the Astra’s crank sensor?
Many GM engines benefit from a CKP variation learn using a compatible scan tool after sensor replacement. It helps the ECM correctly interpret crank signals for misfire detection and timing control. Check GM Service Information for your exact engine, if available, performing the relearn is best practice.