Conventional Cruise Control

DESCRIPTION 

An electronic speed control (also known as cruise control) system is standard factory-installed equipment on this vehicle. The electronic speed control system includes the following major components, which are described in further detail elsewhere in this service information:

• Body Control Module  - The Body Control Module (BCM) located in the passenger compartment receives the hardwired inputs from the cruise control switches and the stop lamp switch, then relays those inputs to the Powertrain Control Module (PCM) over the Controller Area Network (CAN) data bus. Refer to MODULE, BODY CONTROL (BCM), DESCRIPTION AND OPERATION .
• Brake Lamp Switch  - The brake (also known as stop) lamp switch is located on the brake pedal support bracket under the driver side of the instrument panel. Refer to LAMPS/LIGHTING - EXTERIOR, DESCRIPTION AND OPERATION .
• Instrument Panel Cluster  - A CRUISE indicator is located in the Instrument Panel Cluster (IPC) that provides an indication to the vehicle operator when the speed control system is turned ON. Refer to INSTRUMENT PANEL CLUSTER, DESCRIPTION AND OPERATION .
• Powertrain Control Module  - The PCM located in the engine compartment contains the software and hardware that monitors all of the speed control system inputs and controls all of the speed control system outputs. Refer to MODULE, POWERTRAIN CONTROL (PCM), DESCRIPTION AND OPERATION .
• Speed Control Switch Stalk  - A speed control switch containing selectable speed control options is located in the stalk attached to the left side of the steering column.
• Wheel Speed Sensors  - A wheel speed sensor is located on the knuckle of each front and rear wheel. Refer to BRAKE SYSTEM, DESCRIPTION AND OPERATION .

The BCM, the PCM and the IPC each contain programming that allow them to communicate with each other using the CAN bus. This method of communication is used by the BCM to relay the status of the speed control switches to the PCM, and by the PCM for control of the CRUISE indicator in the IPC. Refer to COMMUNICATION, DESCRIPTION AND OPERATION .

OPERATION 

The speed control switch stalk located to the left on the left side of the steering column controls all speed control system features. When a selection with the switch is made, it provides a hard-wired resistor multiplexed analog input to the Body Control Module (BCM). The BCM is a gateway to the Controller Area Network (CAN) data bus and monitors the hard-wired speed control switch and stop (brake) lamp switch inputs, and sends these inputs to the Powertrain Control Module (PCM) through the CAN bus.

The PCM continually monitors these inputs, as well as electronic vehicle distance  message inputs from the Antilock Brake System (ABS) module, along with other inputs, and provides the appropriate outputs to perform the requested electronic speed control features.

The PCM constantly monitors the speed control system electrical circuits to determine the system readiness. The PCM will set the appropriate Diagnostic Trouble Code (DTC) if a monitored system fault is detected.