I actually find new electronic automotive systems to be easier than the "old way" (tracing wires, probing with a multimeter, etc.): oftentimes the issue will ha

I actually find new electronic automotive systems to be easier than the "old way" (tracing wires, probing with a multimeter, etc.): oftentimes the issue will have diagnosed itself, and, if not, the ECU diagnostic tool will have an actual value display and a list of actuators you can hit to see if the sensor responds appropriately. I've never seen a sensor that's more than about $150, but I'm sure they're out there. The frustrating part (which is indeed common to German cars and high-end tractors) is that the diagnostic systems are all loaded with unnecessary and ridiculous manufacturer protectionism. You can't even clear the "Change Oil" light on a new Porsche without a Porsche diagnostic system or the reverse-engineered clone tool (Durametric). And even once you've found a broken sensor or component, it's often pointlessly "coded" (its serial number written into an EEPROM) such that the factory diagnostics tool needs to bless its replacement.