Steering Column Control Module
DESCRIPTION
The Steering Column Control Module (SCCM) (1) is located near the top of the steering column below the steering wheel. The SCCM includes the clockspring, the left (lighting) multifunction switch, the right (wiper) multifunction switch, and a steering column power tilt and telescope switch (if equipped).
Do not replace the SCCM for any Steering Angle Sensor (SAS) fault or issue since the SCCM does not contain the SAS. For SAS description and operation. Refer to DESCRIPTION AND OPERATION .
The SCCM is secured to the steering column by an integral band clamp on the bottom of the instrument panel side of the SCCM. The SCCM has a centering attachment screw located on the top of the instrument panel side of the SCCM to be certain the SCCM is centered properly on the steering column.
There are also unique lugs cast into the outer circumference of the steering wheel hub that must be engaged into slots within the inner circumference of the clockspring rotor hub to unlock and drive the clockspring. The steering wheel must be tightened to specification to ensure proper clockspring function.
Verify the paint mark on the 24 mm nut is visible prior to installing and torquing to specification.
The SCCM includes three integral connector receptacles that face toward the Driver AirBag (DAB) (front side) and are connected to the steering wheel electrical components through three take outs and connectors of the steering wheel wire harness. The 6-terminal receptacle at the 11 o'clock position contains the circuits for the DAB. The 12-terminal receptacle at the 1 o'clock position contains the circuits for a Local Interface Network (LIN) data bus to the Body Control Module (BCM) for the Electronic Vehicle Information Center (EVIC) switch data transmission, another LIN data bus for transmission of cruise control and Hands On Detection data, the horn signal, B(+) feed and ground for the LIN module (internal to the SCCM), steering wheel heater Negative Temperature Coefficient (NTC) feedback, and shifter paddle feedback (if equipped). The 2-terminal receptacle at the 5 o'clock position contains the heated steering wheel B(+) feed and return circuits to the Comfort Steering Wheel Surface Module (CSWSM) (if equipped). Both radio control switches are hardwired to the EVIC switch on the left steering wheel spoke, which then uses the LIN data bus to communicate with the BCM. The surface of the rotor hub facing the steering wheel (front side) also has a 6-terminal single connector for the Driver AirBag (DAB) with a Connector Position Assurance (CPA) lock. The pigtail connector contains the circuits for DAB function.
The SCCM also includes two integral connector receptacles that face toward the instrument panel (back side) and are connected to the vehicle electrical system through two take outs and connectors of the instrument panel wire harness. The 14-terminal receptacle at the 6 o'clock position contains the circuits for heated steering wheel (if equipped) from the CSWSM and the Driver AirBag (DAB) from the Occupant Restraint Controller (ORC) module. The 16-terminal receptacle at the 9 o'clock position contains the circuits for the EVIC LIN data bus and the cruise and Hands On Detection LIN data bus to the BCM, the horn signal to the BCM, steering wheel heater Negative Temperature Coefficient (NTC) signal and return, shifter paddle signal and return (if equipped), fused B(+), ground and the Controller Area Network - Chassis (CAN-C) data bus.
The SCCM cannot be adjusted or repaired. If ineffective or damaged, the entire SCCM must be replaced as a unit.
OPERATION
The SCCM includes an electronic circuit board with a microcontroller. The SCCM microcontroller provides power and ground to the multifunction switches and the power tilt and telescope steering column switch (if equipped) of the SCCM, then utilizes integrated circuitry to monitor digital return inputs from each of these switches. The circuits for the horn switch, the optional heated steering wheel, the standard equipment Driver AirBag (DAB), the paddle shifter switches and the cruise switches are all pass-through circuits of the SCCM.
The switch pods in the left and right horizontal spokes of the steering wheel are each LIN bus slave nodes. The switch states of the hands free communication switches and the EVIC control switches in the left switch pod are communicated over the LIN bus directly to the LIN bus master node of the BCM. The left switch pod also controls the back lighting of both switch pods. The switch states of the speed control switches in the right switch pod are communicated over the LIN bus to the LIN master node of the BCM.
Two fixed connector receptacles on the SCCM connect to the instrument panel wire harness via two wiring harness connectors.
The tilt/telescope switch is located on the lower left of the SCCM. The position data is transmitted from the SCCM via CAN-C message to the BCM.
The SCCM is connected to a fused B(+) circuit and receives a path to ground at all times. These connections allow it to remain functional regardless of the ignition switch status until sleep mode occurs. Any input to the SCCM that controls a vehicle system function that does not require that the ignition switch status be ON such as pressing the optical horn switch, prompts the SCCM to wake up and transmit on the CAN-C data bus.
The service replacement SCCM is shipped with the clockspring centered within the SCCM and with a plastic locking tab installed. This locking tab should not be removed until the SCCM has been properly installed on the steering column. If the locking tab is removed before the steering wheel is installed on a steering column, clockspring centering must be confirmed by viewing the inspection window on the clockspring rotor. If the black boxes of the clockspring tape are not visible in the inspection window, the entire SCCM must be replaced with a new unit. Refer to MODULE, STEERING COLUMN CONTROL (SCCM), REMOVAL AND INSTALLATION .
The hardwired circuits between components related to the SCCM may be diagnosed using conventional diagnostic tools and procedures. Refer to the appropriate wiring information. The wiring information includes wiring diagrams, details of wire harness routing and retention, connector pin-out information and location views for the various wire harness connectors, splices and grounds. For proper wire repair, and connector repair procedures. Refer to STANDARD PROCEDURE and Refer to REMOVAL . Refer to INSTALLATION .
However, conventional diagnostic methods will not prove conclusive in the diagnosis of the SCCM or the electronic controls and communication between modules and other devices that provide some features of the SCCM. The most reliable, efficient and accurate means to diagnose the SCCM or the electronic controls and communication related to SCCM operation requires the use of a diagnostic scan tool. Refer to the appropriate diagnostic information.