Toyota RAV4 > Engine electrical systems > Battery — disconnection and reconnection

Battery — disconnection and reconnection


Warning: Hydrogen gas is produced by the battery, so keep open flames and lighted cigarettes away from it at all times. Always wear eye protection when working around the battery. Rinse off spilled electrolyte immediately with large amounts of water.

Warning: Always disconnect the cable from the negative battery terminal FIRST and hook it up LAST or the battery may be shorted by the tool being used to loosen the cable clamps.

1. Some systems on the vehicle require battery power to be available at all times, either to maintain continuous operation (alarm system, power door locks, etc.), or to maintain control unit memory (radio station presets, Powertrain Control Module and other control units). When the battery is disconnected, the power that maintains these systems is cut. So, before you disconnect the battery, please note that on a vehicle with power door locks, it’s a wise precaution to remove the key from the ignition and to keep it with you, so that it does not get locked inside if the power door locks should engage accidentally when the battery is reconnected!

2. Devices known as «memory-savers» can be used to avoid some of these problems. Precise details vary according to the device used. The typical memory saver is plugged into the cigarette lighter and is connected to a spare battery. Then the vehicle battery can be disconnected from the electrical system. The memory saver will provide sufficient current to maintain audio unit security codes, PCM memory, etc., and will provide power to always hot circuits such as the clock and radio memory circuits.

Warning: Some memory savers deliver a considerable amount of current in order to keep vehicle systems operational after the main battery is disconnected. If you’re using a memory saver, make sure that the circuit concerned is actually open before servicing it.

Warning: If you’re going to work near any of the airbag system components, the battery MUST be disconnected and a memory saver must NOT be used. If a memory saver is used, power will be supplied to the airbag, which means that it could accidentally deploy and cause serious personal injury.

3. To disconnect the battery, turn the ignition to Off and remove the key. Ensure the headlights and any other electrical loads are off.

4. Loosen the cable end bolt and disconnect the cable from the negative battery terminal. Isolate the cable end to prevent it from coming into accidental contact with the battery terminal.

5. After disconnecting the negative battery terminal, if necessary, the positive battery terminal can now be disconnected.


6. Reconnect the positive battery terminal first (if disconnected).

7. Reconnect the negative battery cable last.

8. The clock, audio settings and radio station presets will need to be reset after reconnecting the battery.

9. If equipped, reset the moon roof. See Reset moon roof position procedure.

10. If the back door was open when the battery was disconnected and reconnected, perform the Reset back door close position procedure.

Reset moon roof position

11. Turn the ignition on (vehicles without smart key system) or Ignition On mode (vehicles with smart key system).

12. Press and hold the moon roof Close or Up switch until the moon roof tilts up, pauses for about one second, then tilts down and fully opens and closes. After the movement, release the switch.

13. Verify proper operation of the automatic operation and repeat the procedure as necessary.

Reset back door close position

Note: This procedure is not required if the back door was closed while the battery was disconnected and reconnected.

14. With the back door in the open position, reconnect the battery.

15. Close the back door and verify proper operation.

  • Pages

    open all | close all