Repeated Sensor Failures – Camshaft/Crankshaft – Seeking Help

Hi everyone,

I’m dealing with a frustrating issue in my Volkswagen Passat B8 and I hope someone here can help or offer insight.

Here’s the timeline:
1. After owning the car for a while, I started experiencing jerking/hesitation while driving.
2. Then the car became hard to start, especially after sitting for a while.
3. A scan showed Camshaft Position Sensor (Camshaft Axle Sensor) as the fault — I replaced it, but the problem got worse, not better.
4. I then took the car to an official Volkswagen dealership, and after full diagnostics, they confirmed the issue was with the Crankshaft Sensor.
5. I replaced the Crankshaft Position Sensor, and the issue disappeared completely... For about a week.
6. After a week, the starting issue came back — the engine cranks for a long time before it starts.
7. I scanned the car again, and now the fault shows up as Camshaft Sensor again.
8. I replaced the battery with a new AGM battery, thinking it might be a voltage issue — but the same Camshaft Sensor fault came back after 2–3 days.

Now I’m stuck and seriously confused. My questions:
• Why do these sensors keep failing or triggering faults?
• Could this be caused by bad wiring, poor grounding, or ECU-related issues?
• If it’s wiring, why didn’t Volkswagen detect it? I asked them to fully inspect the system, and they claimed everything was fine.
• Is it possible that voltage instability, faulty grounds, or a bad relay/fuse is affecting the sensors?
• Has anyone experienced a similar issue with the B8 platform?

This has turned into an expensive guessing game, and I’d really appreciate any insight or advice from those who have seen similar issues.

Thanks a lot!