Hybrids combine ICE and EV systems — and the failure modes of both. Understand the architecture before you diagnose.
Hybrid HV systems are no less dangerous than full EV. Same gloves, same procedures.
Series (ICE only charges battery, motor drives wheels — e.g. range extender). Parallel (ICE + motor both drive wheels — most mild hybrids). Power-split (planetary blends both — Toyota HSD). PHEV (any of the above with a larger pack + plug).
Treat HV side like an EV. ICE side is normal maintenance — but most hybrids run the ICE less, so oil ages by time, not just miles. Cooling system for inverter + battery is critical to pack life.
Yes — the ICE still uses oil. Most OEMs spec a time-based interval (e.g., 1 year) regardless of mileage.