1. Aging naturally, raining, moisture, corossion from snow melting agent might cause the socket poor contact, or wiring deteriorate which lead to reverse light flickering.
2. Long operating hour causing overuse of bulb filament might also cause flickering to the light.
Suggest to repair at workshop as soon as possible.
1. Check if there is check light or error message in the meter cluster, identify the malfunction item.
2. Take out the reverse lamp light bulb, check if it is broken, the bulb filament if melted or bulb surface have burnt mark.
3. Take the bulb faulty as an exclusion, use the multimeter to check the resistance of the wiring to confirm whether the problem is cause by wiring faulty or poor contact on the socket.