On Tacoma you must disconnect the battery cable at its negative terminal followed by disabling voice app security when it exists. After disconnecting power, disable airbags and remove steering wheel components to get access by taking off protective steering column shields. Pull away the starter switch bezel and disconnect its electrical connectors from the ignition part. Using an ohmmeter test all switch connections: the LOCK position should have no continuity but ACC enables connection between terminals 2 and 3. In ON mode you should see links between terminals 2, 3, 4 and 6, 7. When starting the engine terminals 1, 2, and 4 as well as 6, 7, and 8 need to be connected. Test the key unlock warning switch between OFF mode and the key removed until you find no connection between the two terminals. Insert your key and turn the switch ON to validate 1 and 2 terminal connection. The replacement of ignition switch becomes necessary when manual operation fails. First insert the key into the ignition switch Ignition Lock Cylinder then switch it to ACC mode. Next follow this step by inserting a small screwdriver to depress the release button while pulling the lock cylinder straight out. The process to install a part follows the opposite steps of when you took it out.