12 Volt 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 system and/or 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 battery cable from the battery first.
Disconnect the positive cable from the battery.