ATEMU simulates most critical features of particular Toyota / Lexus auto transmissions which were available for UZ / JZ equipped vehicles since 1998. This makes it possible to obtain rated power from engine when using factory ECU and any transmission other than that ECU is designed to work with. Factory ECU would otherwise enter limp home mode with significant power and torque loss (for example, VVTi set to max retard for 1997-2000 Lexus LS400) Some non-critical error codes remain intact for simplicity of installation and reducing the cost for off-road application. These codes can be easily addressed with additional components if emission test has to be passed for street legal application.