Hello and thanks for your question in the autoaid Community.
This fault Code means: CONTROL MODULE, SUPPLY VOLTAGE TOO LOW (UNDERVOLTAGE)
You have to Check the Battery, also measure the loading Voltage from the Generator to the Battery. If this car isn‘t always in usw, you should reload the Battery.
But let Check the Battery with a Battery Test. If there is a Problem, then you should replace the Battery.

Greetings
Team autoaid