The Smart High Beam is a system that automatically adjusts the headlamp range (switches between high beam and low beam) according to the brightness of other vehicles and road conditions.
Hyundai Sonata LF 2014-2019 Service Manual: Thermostat Repair procedures
Removal
Disassembly of the thermostat would have an adverse effect, causing a lowering of cooling efficiency.
1.
Drain engine coolant so that its level would be under the thermostat height.
2.
Remove the radiator lower hose.
(Refer to Cooling System - "Radiator Hose ...
Hyundai Sonata LF 2014-2019 Service Manual: Stop Signal Electronic Module Repair procedures
Inspection
1. Fuse inspection
Mount the test fuse to the switch fuse and relay fuse part to confirm a normal joint fit.
2. Inspection of connector by each part
Check to see whether or not each connector has been damaged, or terminal surge, or incomplete connection has taken place
[Engine room ...