Electronics play an increasingly vital role in modern cars. Depending on your make and model, certain maintenance tasks will require a diagnostic tool either to carry out the procedure, or reset the dashboard service indicator.
On older vehicles, not resetting the service lamp may not have consequences, but it’s essential for newer cars, or else certain functions might not work correctly. For example, a car that thinks its engine oil is still old might not permit active regeneration of its diesel particulate filter (DPF), causing the exhaust to block eventually.
A decent diagnostic tool is also useful to interrogate the various functions of the car, to ensure that no faults have been flagged-up. Most competent garages can carry-out this procedure, but it is also worth doing it from home.
Like any tool, diagnostic equipment varies in price and it's worth seeking out the best value hardware and software, based on your car’s age and the DIY tasks you might wish to attempt.