Battery Terminal Disconnection and Reconnection: Disconnection

NOTE: Some systems store data in memory that is lost when the battery is disconnected Do the following procedures before disconnecting the battery

Make sure you have the anti-theft code(s) for the audio and/or the navigation system (if equipped)
Make sure the ignition switch is in LOCK (0)
Disconnect and isolate the negative cable from the battery
NOTE: Always disconnect the negative cable from the battery first
Disconnect the positive cable from the battery