Control module supply voltage low
Where to start
Low module supply voltage. The first suspect is the battery: measure the voltage while parked — below 12 volts is already too little, and below 11.8 the modules start dropping off. ⚠️ This code almost never comes alone: with a sagging supply the car throws lost-communication codes for all sorts of modules, and people set off hunting faults that do not exist. The rule is simple — charge or replace the battery first, clear everything, drive, and only then look at what is left. The second most common cause is a corroded terminal or a body earth: the voltage at the battery looks fine while not all of it reaches the module.
How to put together a report a mechanic will actually read
How the code is built
All codes in «Body, airbags and lighting»
How the app helps
CarScan reads this code from your car through an OBD-II adapter, shows whether it is active now or only stored, names the module that reported it, and puts it into a plain-text report for your mechanic.