Description & Operation
WARNING:
Deactivate air bag system before performing any service operation. See AIR BAG RESTRAINT SYSTEMS article. DO NOT apply electrical power to any component on steering column without first deactivating air bag system. Air bag may deploy.
The multiplex control system consists of a body Electronic Control Unit (ECU), tilt and telescopic ECU, and related wiring (communication bus). See Fig 1. The multiplex control system is also equipped with a self-diagnostic function. The communication bus is self-diagnosed by the body ECU which stores an appropriate Diagnostic Trouble Code (DTC) if a fault is detected.
NOTE:
The body ECU is also referred to as instrument ECU or instrument panel ECU.