Conventional Speed Control
The conventional electronic speed control system includes the following major components, which are described in further detail elsewhere in this service information:
- Antilock Brake System Module - An Antilock Brake System (ABS) module is located below the antilock brake Hydraulic Control Unit (HCU) in the engine compartment. Refer to MODULE, ANTI-LOCK BRAKE SYSTEM, DESCRIPTION .
- Brake Lamp Sensor - The brake (also known as stop) lamp switch in this vehicle is actually a brake pedal position sensor. This sensor is located on the brake pedal support bracket under the driver side of the instrument panel. Refer to DESCRIPTION .
- Instrument Panel Cluster - An indicator located in the Instrument Panel Cluster (IPC) displays "CRUISE" to inform the vehicle operator when the speed control system is turned ON. Refer to DESCRIPTION .
- Powertrain Control Module - The Powertrain Control Module (PCM) is located in the engine compartment. The PCM contains the software and hardware that monitors all BUSSED and hardwired inputs related to the speed control system. Along with monitoring the inputs the PCM controls all of the speed control system outputs. Refer to MODULE, POWERTRAIN CONTROL, DESCRIPTION .
- Speed Control Switches - A speed control switch pod containing five momentary switch push buttons is located in the right horizontal spoke of the steering wheel. The switches communicate over the LIN bus system.
- Steering Column Control Module - A Steering Column Control Module microcontroller is internal to the SCCM located at the top of the steering column just below the steering wheel. Refer to MODULE, STEERING COLUMN CONTROL, DESCRIPTION .
- Wheel Speed Sensors - A wheel speed sensor is located on the knuckle of each front and rear wheel. Refer to SENSOR, WHEEL SPEED, FRONT, DESCRIPTION .
The ABS, the IPC, the PCM and the SCCM each contain a microcontroller and programming that allow them to communicate with each other using the Controller Area Network (CAN) data bus. This method of communication is used by the SCCM microcontroller to relay the status of the speed control switches over a dedicated LIN bus to the PCM, and by the PCM for control of the CRUISE indicator in the IC. Refer to COMMUNICATION, DESCRIPTION .
Hard wired circuitry connects the conventional electronic speed control system components to the electrical system of the vehicle. These hard wired circuits are integral to several wire harnesses, which are routed throughout the vehicle and retained by many different methods. These circuits may be connected to each other, to the vehicle electrical system and to the speed control system components through the use of a combination of soldered splices, splice block connectors, and many different types of wire harness terminal connectors and insulators. Refer to the appropriate wiring information. The wiring information includes wiring diagrams, proper wire and connector repair procedures, further details on wire harness routing and retention, as well as pin-out and location views for the various wire harness connectors, splices and grounds.