My 2023 Fabia started throwing up two faults. First the windshield wipers stop working and there's a fault about that. So far I have been able to get them started again by turning them on and off a few times. Then another fault happens in rapid succession and the lane assist stops working. I have an extended warranty until September but the dealer suggested it might be out of warranty because I recently had an oil service, MOT, and new tyres fitted at a local garage. Any advice welcome.

Welcome to the forum.

I believe that a refusal of warranty for items completely unrelated to the servicing work you had done at an independent garage may be not legal under UK consumer law.

See EU block exemption law.

Edited yesterday at 14:281 day by Warrior193
added information

@MoCheshire

Check the battery.

The Lane Assist "Troubleshooting" guidance in my Fabia Mk4's Owner's Manual reads as follows:

So, if there's a windscreen wipers-related fault, it seems not unreasonable that this might disable operation of Lane Assist.

Regarding the warranty, the answer Skoda gave to the FAQ "Can I go to a non Skoda retailer for servicing?" was

You are of course free to choose where you have your vehicle serviced. However, we would always recommend that a Škoda Retailer is used as they receive full training in the servicing of Škoda vehicles and are kept up-to-date with technical information. Having a service completed at a non-franchised retailer will not in itself invalidate the warranty. However, should any difficulty arise that is deemed to be as a direct result of incorrect/incomplete servicing, any remedial work required would not be covered under your new vehicle warranty.

Good calls on consulting the car's 'Owner's manual', muck on the sensor area of the windscreen and the FAQ answer.

However from VW - "2. Switch off the engine and restart it after a while" - what computer engineering progress. 😆 😁 😄 The old "Have you tried switchin' it off 'n' on agen?"

Many years ago my wife won a raffle prize for a Land Rover off-road driving experience and as we're not far from Rockingham Speedway she elected to take it there. Unfortuanately only BMW X5 things were available on the day but she stuck with it and being risk adversed took out the optional £20 insurance cover. The report paper at the end had "poor blue pole" as on the hill decent the vehicle slid into a blue pole and she was blamed for putting her foot on the brake pedal which she didn't (but unlike me she nearly always avoids confrontation) so didn't argue too much against it. Before the end of the course she recieved an apology as based on her denial they checked and it turned out "a sensor had mud on it" !! on what's supposed to be an off-road vehicle !! She wanted to drive a (proper) old Landie rather than some modern (at the time) German machine that drove her, another lesson learnt.