The steering wheel and column has 4 primary functions:

The steering wheel is the first link between the driver and the vehicle. The steering wheel is fastened to a steering shaft within the column. At the lower end of the column, the intermediate shaft connects the column to the steering gear.

Theft deterrent components are mounted and designed into the steering column. The following components allow the column to be locked in order to minimize theft:

The steering wheel and column may also have driver controls attached for convenience and comfort. The following controls may be mounted on or near the steering wheel or column.

The energy-absorbing steering column compresses in the event of a front-end collision, which reduces the chance of injury to the driver. The mounting capsules break away from the mounting bracket in the event of an accident.

The tilt/telescoping steering column has a four-position switch which may be used to adjust the position of the steering wheel in or out (telescope) and up or down (tilt). The position of the column may be changed as follows:

The steering column tilt/telescoping module (SCCM) receives inputs from the tilt/telescope switch to manually move the column to a desired position. Pressing the tilt/telescope switch sends an input to the SCCM. When the SCCM receives an input, it actuates the corresponding column motor.

Pressing the switch momentarily in either the UP or DOWN, or IN or OUT (releasing it within 0.5 seconds) position, causes the column to "jog" a slight distance, in the corresponding direction then stop. This feature allows fine control of the steering column position in each direction. If the switch is pressed and held (for longer than 0.5 seconds), the column "jogs" a slight distance in that direction, pauses, then resumes movement as long as the switch is Pressed.

Both the tilt and telescoping motors are reversible. For example, the tilt motor moves the column both up and down. When the SCCM receives an input to move the column up, it supplies battery positive voltage and ground to the tilt motor in order to move the column up. When the SCCM receives a column down input, it supplies battery positive voltage and ground to the same motor, but with a reverse polarity. When the voltage polarity is reversed and the motor runs in the opposite direction, it moves the column down.

After replacement of the steering column tilt/telescoping module, it is necessary to program the tilt/telescoping soft stops. Each soft stop is a programmable end of travel that is set approximately 0.5 inch (1.3 cm) from the mechanical end of travel. The steering column has a soft stop set at each end of the tilt up/down movement and at each end of the telescoping in/out movement. The system uses soft stops to prevent wear on the system by ensuring that the steering column movement stops before it reaches its mechanical end of travel in any direction. The soft stops are initially programmed at the factory. The stop positions may be reprogrammed, which is necessary any time the steering column tilt/telescoping module is replaced, as described in Steering Column Control Module Programming .

Two position sensors are used by the SCCM to store column positions in memory and to return the column to the stored memory positions. The SCCM provides a 5 volt reference voltage and a ground to both the tilt and telescoping position sensors. The sensor feedback circuit voltage varies from 0.25 volts to 4.75 volts. Each sensor is mounted to its corresponding motor cable assembly. When the motor rotates its cable, the resistance of the sensor varies. The SCCM monitors the feedback voltage to determine the column position via the tilt and telescoping position sensor input circuits. When an entry or exit position is saved, the SCCM stores the column positions by recording each position sensor's feedback voltage. When an entry or exit position is commanded, the module moves the motors until all the position sensor feedback voltages equal the feedback voltages stored in memory.

Memory settings and the personalization of steering wheel positions are available with the tilt/telescoping steering column. The data stored consists of entry positions and exit positions. The entry position is the position that the steering column moves in when the ignition is turned ON. The exit position is the direction that the steering column moves in when the ignition is turned OFF and the driver's door is opened.

An initial memory setting is set in the steering column tilt/telescoping module (SCCM) at the assembly plant. This setting may be changed or "personalized" by the customer at the time of purchase or anytime in the future.

The steering column tilt/telescoping module (SCCM) stores personalization information. The driver information center (DIC) is used to enable and disable the personalization feature in the steering column tilt/telescoping module (SCCM). A Class 2 message is sent to the SCCM, by the driver information center (DIC), which specifies that the SCCM enable the personalization feature until disabled again using the DIC.

The tilt/telescoping steering column module can store six possible positions, three entry positions and three exit positions.

When the driver door switch assembly (DDSA) receives inputs from the memory function switch, the steering column personalization positions may be recorded for one or two different drivers. Once a steering column driving (entry) or exit position is adjusted by the driver it must be set in memory. To record a position, the driver must press the SET MEMORY button, which is followed by a chime to acknowledge that input. Within 5 seconds, either the MEMORY 1or MEMORY 2 button must be pressed. When the DDM receives these inputs, it sends a Class 2 message to the SCCM. The SCCM records the feedback voltages from the column position sensors for that driver. A single chime is sounded to acknowledge that the position was recorded.

To record a second position, the second driver must press the SET MEMORY 2 button, after they have made the apropriate adjustments, and the process continued.

When the driver presses the MEMORY 1 or MEMORY 2 button, the DDSA receives the input and a single chime is sounded. The DDSA sends a Class 2 message to the SCCM indicating which driver memory setting has been selected. The SCCM applies both battery positive voltage and ground to the column motors until all the column position sensor feedback voltages equal the feedback voltages stored in memory for the appropriate driver.

When a keyless entry transmitter is used to unlock the vehicle doors, the remote function actuator (RFA) module communicates which driver key fob performed that command. The steering column tilt/telescoping module (SCCM) recieves the unlock command via a Class 2 message from the remote function actuator (RFA) module.

If the vehicle is the DeVille Touring Sedan (DTS), it is equipped with a floor mounted console gear shifter, and has a column ignition lock system in the steering column as an added safety feature. The column ignition lock systems purpose is to prevent the steering wheel from being locked when the transmission is in gear and the vehicle may still be moving.The column ignition lock system consists of the rear integration module (RIM), the lock cylinder relay, and the park key lock actuator. The park key lock actuator contains a pin that is spring loaded out to mechanically prevent the ignition key cylinder from being turned to the lock position when vehicle speed is above 5 mph for 15 seconds and the transmission is not in the Park position. If vehicle power is lost, and/or the transmission is not in the Park position the operator will not be able to turn the ignition key to the lock position and will not be able to remove the ignition key from the column. For situations where the vehicle must be towed, the system can be overriden by pressing a release button that is reached through an access hole located on the under side of the steering column. A black plug covering the hole must first be removed.

The energy absorbing and locking steering column includes three important features in addition to the steering function.

1. The steering column is energy absorbing and is designed to compress in a front-end collision which will lessen the chance of injury to the driver.
2. The steering column has a tilt/telescoping control system that consists of an electronic control module capable of Class 2 serial data communication, a steering column power assembly with positioning motors and sensors, and a steering column control switch.
3. The multi-function lever provides for the control of the headlamp high beams, and the windshield washer and wiper.

The steering column may be removed, disassembled and reassembled with relative ease. It is important to use only the specified screws, bolts and nuts and to tighten them to the specified torque in order to ensure the proper energy absorbing functions. When the steering column assembly is removed from the vehicle, special care must be taken in handling it. Avoid the use of a steering wheel puller other than the special one recommended in this manual. Sharply striking the end of the steering shaft, leaning on the assembly or dropping the assembly could shear off or loosen the plastic fasteners which maintain the steering column rigidity.