2003 Mercedes-Benz C-Class memory loss

what is the cause of memory loss in a car

Strange, I have memory loss no matter where I am. But if you can be more specific on what memory loss you’re experiencing, it would be helpful.

I guess you mean the car has a memory loss. Not that you experience memory loss while in your car.
Two reasons
Short term memory loss is caused by disconnecting the battery, the car will have to ‘relearn’ engine and transmission settings. How it does it varies by make, somerelearn by simply idling for 30 seconds then driving normally, some are more involved. Should be in theowners manual.
Long term or total memory loss—computer failure.

Some memory loss is due to small batteries contained inside a device. My Saab had such a battery in the alarm system and required replacement at 15 years to make the alarm shut up. Another resided, I think, in the radio. If the battery was disconnected the radio and car lost their “marriage” and the radio refused to work. That’s when I sold the car.

Is your radio not working?

If I guess at what you really mean, I’d say your battery is on the way out.