Driver Side Switch Module LIN Communication Malfunction: Description
WARNING: This page is about a different car, the 2008 Lexus LS 600hL. However, it is still accessible from the selected car via links, so may be relevant.
The outer mirror switch monitors the LIN communication bus between the components related to the switches on the driver side seat
HINT:
DTC U1127, U1128 and U1129 are output simultaneously when- 1) there is an open or short in the LIN communication bus between the switches on the driver side seat, and 2) their LIN communication bus stops.