Steering Column Module - Description

DESCRIPTION





This vehicle is equipped with a Steering Control Module (SCM), which is an electronic circuit board with a microprocessor that is internal to the multi-function switch (1) housing. The SCM is a Local Interface Network (LIN) slave and communicates over a dedicated LIN bus circuit with the ElectroMechanical Instrument Cluster (EMIC) (also known as the Cab Compartment Node/CCN), which is the LIN master and also provides a gateway to the Controller Area Network (CAN) data bus.

The multi-function switch is located on the left side of the steering column, just below the steering wheel. The multi-function switch provides the primary controls for the front and rear wiper and washer systems, the turn signals and for headlamp beam selection. The only visible component of the switch is the control stalk, which includes a control sleeve or ring and a control knob that extend through the shrouds on the left side of the steering column. The remainder of the switch including its mounting provisions, its electrical connection and a turn signal cancel actuator are concealed beneath the shrouds.

The switch housing and controls are constructed of molded black plastic. A single integral latch feature and slide tabs on the switch housing engage channels and a striker that are integral to the left side of the mounting bracket that is integral to the clockspring (3) to secure the switch to the steering column. Each of the switches within the multi-function switch is internally connected to the SCM. A single connector receptacle integral to the back of the switch housing connects the SCM to the vehicle electrical system through a dedicated takeout and connector of the instrument panel wire harness.

The SCM cannot be adjusted or repaired, and is not flash update capable. If ineffective or damaged the entire multi-function switch must be replaced. Multifunction Switch - Removal. The clockspring (with the multi-function switch mounting bracket) and the multi-function switch (with the SCM) are each available for separate service replacement.