# The safety switch The safety switch is part of the safety concept in the DIWA.5 transmission system. The safety switch is an electronic switch in the transmission control unit (ECU) that can de-energize all solenoid valves in the event of a critical situation. The safety switch cannot be closed manually but is actuated by the processor in the transmission control unit. The safety switch is closed during normal driving (also in neutral). The safety switch must be closed for the actuator test. If a critical situation is provided, the safety switch will be opened, an actuator test is not possible. The cause for an open safety switch can be, e.g., a short-circuit to supply voltage at one of the solenoid valves which would shift in a gear with "Neutral selected". Up > Higher-level section © by Voith Turbo GmbH & Co. KG send remarks to joachim.ehleiter@voith.com (electronic department) or r.theilacker@voith.com (electronic department)