Troubleshooting (BMW 7 Series E38)

If a fault is detected in the AT, first check the ATF level (see chapter Vehicle settings and routine maintenance). If the level is insufficient, check the condition of the corresponding seals. Carefully inspect the oil cooler and all ATF hoses, make sure there are no signs of leaks. The vehicle owner can check/replace the information sensors of the AT control system, as well as replace the components of the AT mode selection drive. Before replacing the suspected sensor, query the control unit memory - all significant failures are recorded in the module memory as DTC codes, and in particularly serious cases, the AT automatically switches to emergency operation mode. DTC codes are read using special diagnostic equipment connected to the on-board diagnostic system connector (DLC) (see chapter Engine electrical systems). In the absence of access to the necessary devices, it will be enough to try to at least qualitatively determine the nature of the failure (electrical/mechanical) in order to facilitate communication with car service specialists. You should not start removing the AT prematurely, since its diagnostics are only possible in the installed position.