Transfer Case: Precaution: Precautions

Before connecting or disconnecting the Transfer control unit harness connector, turn ignition switch OFF and disconnect negative battery terminal. Failure to do so may damage the Transfer control unit. Because battery voltage is applied to Transfer control unit even if ignition switch is turned off.
When connecting or disconnecting pin connectors into or from Transfer control unit, take care not to damage pin terminals (bend or break).
Make sure that there are not any bends or breaks on Transfer control unit pin terminal, when connecting pin connectors.
Before replacing Transfer control unit, perform Transfer control unit input/output signal inspection and make sure whether Transfer control unit functions properly or not. See TRANSFER CONTROL UNIT INSPECTION TABLE under TROUBLE DIAGNOSIS - GENERAL DESCRIPTION.