Saving memory after battery removal

With some electronic devices on vehicles, it is necessary to save memory after removing the battery. When they are without power, such electronic devices lose their stored data.

Electronic modules in vehicles, such as radio and driver settings, require a small amount of energy to store their memory (KAM). When removing the battery, the memory of certain electronic systems is lost. For some electronic systems, memory loss can be problematic. The electronic control unit can lose its adaptive learning data, meaning it will need to recollect this information throughout driving which can take several days. For other systems, such as the security system, memory loss can prevent the vehicle from restarting or using the radio.

Check manufacturer and owner information to determine which systems will be affected by the power loss. You must identify each system that requires restarting security or initialization codes and ensure that procedures and equipment are available to reinitialize the system or module. In case of loss of codes, they can be requested by contacting sellers or manufacturers to reactivate the vehicle’s system.

External sources of 12 volt DC power can save the memory of electronic devices after removing the battery. The external source is connected via the diagnostic socket with the appropriate cable.

External power supply via diagnostic socket

If the cigarette lighter socket is always on, an external power supply can be connected via the cigarette lighter to save memory.

External power supply via the cigarette lighter

When the external memory storage power source is connected, still be careful when working on the vehicle to avoid shorting.

To connect the external power supply to save memory after removing the battery, follow these steps:

Identifying critical modules

In the appropriate service information or owner’s manual, identify the electronic modules that require re-initialization or code entry when the battery is disconnected. Check if there are any recommendations on how to connect the external power supply.

Connecting the external power supply

Use a suitable external power supply and connection method to save the memory. Connect the external power supply using the appropriate connector to the diagnostic socket or the cigarette lighter. After connecting and turning on the external power supply, remove the battery from the vehicle.

Checking after battery installation

After installing and connecting the battery, turn off and disconnect the external power supply. Check all electronic systems on the vehicle (radio, error lights, etc.). In the event of a memory loss, use the correct codes to reactivate the modules as needed.