Hybrid and electric vehicles add current sensors, isolation monitoring, inverter temperature sensors, motor position resolvers, battery-cell voltage sensing and high-voltage interlock circuits. The diagnostic principles of plausibility and circuit integrity still apply, but the safety environment changes dramatically.
High-voltage orange cables and components can remain dangerous even when the vehicle appears off. Diagnostic work may require personal protective equipment, insulated tools, lockout procedures and verification of zero potential according to manufacturer instructions. A standard automotive multimeter may not be suitable for high-voltage measurement.
Beginners can safely learn from scan data and low-voltage sensor concepts, but should not open high-voltage battery packs or probe HV circuits without appropriate training and equipment.
Treat hybrid/EV service boundaries as part of diagnosis. Knowing when not to probe is a professional skill.