Grand Cherokee 2WD V8-5.7L VIN 2 (2005)
Steering Control Module: Description and Operation
MODULE-STEERING CONTROL
DESCRIPTION
WARNING: The Steering Control Module (SCM) must be replaced in the event of a frontal impact event where the front airbags have been
deployed. The clockspring is integral to the SCM and is not reusable.
This vehicle is equipped with a Steering Control Module (SCM) that houses an integral clockspring. It is an interface for switches such as ignition,
lighting, wipers, horn, speed control, and remote radio. The SCM receives switch input and either directly sends or buses the outputs to the proper
destinations. The module communicates via the Controller Area Network (CAN) B data bus. If the vehicle is equipped with ESP, the module is
equipped with a steering angle sensor. Steering angle data is sent over the CAN C data bus.
The Steering Control Module (SCM) is mounted to the steering column shaft. The SCM is located under the steering column shroud and is attached to
the steering column with two screws at the upper portion of the module. A key on the cancel cam indexes with a keyway on the steering shaft. There
are five electrical connections on the column side of the SCM. The module connects to the vehicles wiring harness with two connectors; a 4-way
which is a pass through for the airbag squids, and a 16-way. The other three connectors are for the hazard and multi-function switches and are
concealed when the switches are in place. Any switched input that would cause a vehicle system to function that does not require that the key be ON,
such as turning on the lights or sounding the horn, prompts the SCM to wake up on the CAN data bus network. If equipped with ESP the steering
angle sensor must be recalibrated using the scan tool.
The components that are contained within or attach to the SCM are:
^
Clockspring - The clockspring is integral to and serviced as a unit with the Steering Control Module (SCM).
^
Connectors - The steering wheel side of the SCM contains four connectors. These consist of a 2-way, a 6-way and two squib connectors. Two
short harnesses connect the steering wheel mounted airbag to the clockspring. These circuits pass directly through the SCM and are connected to
the vehicle wiring at the 4-way connector located on the column side of the module. These circuits are directly connected to the ORC. The 6-way
connector contains the horn signal and horn return circuits. The horn is an input to the SCM. The SCM receives the switch input and sends a
bussed message over CAN B Bus. The 6-way connector also contains 2-speed control sense circuits and a speed control sense return. These
circuits pass through and go directly to the PCM.
