Mercedes GLC Diesel hard starting and reduced power

A defective camshaft sensor can certainly cause those symptoms Reduced engine power and difficulty starting are classic signs I’d check the wiring and connections to the camshaft position sensor as you suggested If the error is stored it will need addressing

How exactly do I check the wiring and connections I am not particularly savvy doing that stuff I'm a bit worried about messing something up especially with things like camshaft sensors and timing

Given you're not comfortable with electrical diagnostics and considering the camshaft sensor is crucial for proper engine timing I'd advise taking it to a workshop Improper timing can result in further engine damage Peace of mind is worth something An eventual repair cost shouldn't be more than 95€

Yeah I think you're right taking it to a workshop sounds like the best plan It's booked in for next week Thanks for the advice I appreciate it