Clockspring - Description

DESCRIPTION





The clockspring (2) includes a Steering Angle Sensor (SAS) with an integral and internal Local Interface Network (LIN) data bus master node and a Controller Area Network (CAN) data bus gateway. All of these components are serviced as a unit with the clockspring. The clockspring also includes mounting provisions to which the multi-function switch (1) with an integral LIN data bus slave node internal to the switch housing is secured with integral keyways and a latch feature. The clockspring is secured to the top of the steering column, just below the steering wheel. When combined the clockspring, SAS and multi-function switch are referred to as the Steering Column Control Module (SCCM).

The clockspring case includes integral tabs at the top and bottom for mounting the unit to the steering column housing with three screws. The two upper screws are captive and remain with the clockspring when it is removed. The SAS circuitry is contained within a flat, molded plastic case that is secured to the lower surface of the clockspring case hanging below the steering column. Within the plastic clockspring case is a spool-like molded plastic rotor with a large exposed hub and an integral turn signal cancel cam. The upper surface of the rotor hub has a large center hole, an engagement dowel or drive pin, a single sleeve containing two short driver airbag squib pigtail wires with connectors, and a connector receptacle that faces toward the steering wheel.

Service replacement clocksprings are shipped pre-centered and with a molded plastic locking pin that snaps into a receptacle on the rotor. The locking pin secures the centered clockspring rotor to the clockspring case and during shipment and handling, but must be removed from the clockspring after the steering wheel is installed on the steering column. The clockspring must be replaced if proper centering has been compromised or else the clockspring tape may be damaged and Diagnostic Trouble Codes (DTCs) or faults may be set within the SAS.





The lower surface of the clockspring case (1) facing toward the instrument panel includes two receptacles on the left side. One receptacle (2) is for mounting the multi-function switch. The second receptacle (3) is for mounting an adjustable pedal switch on vehicles that are so equipped. There are two integral connector receptacles (4) on the left lower corner of the clockspring case. The SAS (5) has a dedicated connector receptacle (6) near the right lower corner of that unit.

Within the plastic case and wound around the rotor spool is a long ribbon-like tape that consists of several thin copper wire leads sandwiched between two thin plastic membranes. The outer end of the tape terminates at the connector receptacles that face the instrument panel, while the inner end of the tape terminates at the driver airbag squib pigtail wires and connector receptacle on the hub of the clockspring rotor facing the steering wheel. The rotor spool also includes an integral turn signal cancel cam.

The clockspring cannot be repaired. If damaged, ineffective, if clockspring centering is compromised or if the driver airbag has been deployed, the clockspring and SAS must be replaced as a unit. The multi-function switch with the integral LIN slave node is available for individual service replacement.