The job of a mechanic has definitely become a lot more complicated in recent times. In the past they would never need to diagnose computer faults, but with modern cars and trucks using an ever increasing number of electronic components and pieces of computer hardware today's mechanic definitely needs to know about a lot more than just how to change oil and spark plugs. A variety of systems in a modern vehicle may well rely upon an ECU - electronic control unit. These include systems like suspension and immobiliser.
Some modern vehicles may have up to around 80 ECUs. The software in ECUs has continued to increase in line count, complexity, and sophistication which has meant that a mechanic now needs some very specialised tools in their toolkit in order to diagnose faults. The type of vehicle diagnostics tools that a mechanic therefore needs to use include devices like Jaltest, for HGVs, and for cars the Eclipse EDIS diagnostic device
, produced by Eclipse Automotive Technology Ltd.
, which will interface with the ECUs in a wide range of vehicles and diagnose faults for the mechanic to then work on.
It's easy to see then why working as a mechanic on modern vehicles certainly requires someone to be more than a "grease monkey" and how having the latest electronic tools and knowing how to use them properly is now a crucial part of the job as well.