Precautions for Removing of Battery Terminal

When removing the 12V battery terminal, turn OFF the ignition switch and wait at least 30 seconds.
NOTE: ECU may be active for several tens of seconds after the ignition switch is turned OFF. If the battery terminal is removed before ECU stops, then a DTC detection error or ECU data corruption may occur.
For vehicles with the 2-batteries, be sure to connect the main battery and the sub battery before turning ON the ignition switch.
NOTE: If the ignition switch is turned ON with any one of the terminals of main battery and sub battery disconnected, then DTC may be detected.

Fig 1: Disconnecting Negative Battery Terminal
Courtesy of NISSAN NORTH AMERICA, INC.
After installing the 12V battery, always check "Self Diagnosis Result" of all ECUs and erase DTC.
NOTE: The removal of 12V battery may cause a DTC detection error.