Which element is essential when addressing vehicles post-repair with advanced driver-assistance systems (ADAS)?

Calibrating the systems is crucial when addressing vehicles equipped with advanced driver-assistance systems (ADAS) after repair. These systems rely on precise measurements and functionality to assist drivers safely. Calibration ensures that sensors and cameras are aligned correctly and can interpret information accurately, which is vital for the operation of features like lane-keeping assist, automatic emergency braking, and adaptive cruise control.

Without proper calibration, ADAS components may not perform optimally, potentially leading to safety issues for the driver and others on the road. This step is essential, as it confirms that all changes made during the repair process are recognized by the vehicle’s systems, maintaining the integrity of the safety features designed to protect occupants and prevent accidents.

The other options, while important for vehicle maintenance, do not directly address the critical functioning of ADAS post-repair. Checking battery life, for example, relates more to the vehicle's electrical systems but does not impact the calibration of the ADAS. Performing exterior washes and inspecting transmission fluid are standard maintenance practices but do not engage with the specific technological requirements that ensure ADAS functions correctly.