Commander 2WD V8-4.7L Flex Fuel (2009)
Clockspring Assembly / Spiral Cable: Description and Operation
Clockspring - Operation
OPERATION
The clockspring is a mechanical electrical circuit component that is used to provide continuous electrical continuity between the fixed instrument panel
wire harness and certain electrical components mounted on or in the rotating steering wheel. On this vehicle the rotating electrical components include
the driver airbag, the horn switch, the speed control switch, the remote radio switches and the Electronic Vehicle Information Center (EVIC) control
switches, if the vehicle is so equipped. The clockspring is positioned and secured near the top of the steering column. The fixed connector receptacles on
the back of the fixed clockspring case connect the clockspring to the vehicle electrical system through three take outs with connectors from the
instrument panel wire harness.
The turn signal cancel cam is integral to the rim of the clockspring rotor hub within the clockspring case so it also moves with the rotation of the steering
wheel. Two short, black-sleeved pigtail wires on the upper surface of the clockspring rotor connect the clockspring to the driver airbag, while a steering
wheel wire harness connected to the connector receptacle on the upper surface of the clockspring rotor completes circuits to the horn switch, the speed
control switch and, if the vehicle is so equipped, to the optional remote radio switches and EVIC control switches on the steering wheel. The third
connector receptacle is dedicated to the inputs and outputs of the Steering Angle Sensor (SAS) internal to the clockspring case.
Like the clockspring in a timepiece, the clockspring tape has travel limits and can be damaged by being wound too tightly during full stop-to-stop
steering wheel rotation. To prevent this from occurring, the clockspring is centered when it is installed on the steering column. Centering the clockspring
indexes the clockspring tape to the movable steering components so that the tape can operate within its designed travel limits. However, if the steering
wheel is removed from the steering column, if the clockspring is removed from the steering column, or if the steering shaft is disconnected from the
steering gear, the clockspring spool can change position relative to the other steering components. The clockspring must be re-centered following
completion of this service or the tape may be damaged.
Service replacement clocksprings are shipped pre-centered and with a plastic locking pin installed. This locking pin should not be removed until the
steering wheel has been installed on the steering column. If the locking pin is removed before the steering wheel is installed on a steering column, the
clockspring centering procedure must be performed. See: Service and Repair/Procedures. Proper clockspring installation may be confirmed by viewing
the SAS data using a diagnostic scan tool.
The hard wired clockspring circuits as well as the hard wired inputs and outputs of the SAS may be diagnosed using conventional diagnostic tools and
procedures. Refer to the appropriate wiring information. However, conventional diagnostic methods will not prove conclusive in the diagnosis of the
SAS or the electronic controls or communication between other modules and devices that provide features of the Electronic Stability Program (ESP) or
Supplemental Restraint System (SRS). The most reliable, efficient, and accurate means to diagnose the SAS or the electronic controls and
communication related to ESP or SRS operation requires the use of a diagnostic scan tool. Refer to the appropriate diagnostic information.
