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:
- ABS Module - An BS module is located below the antilock brake HCU in the engine compartment. Refer to MODULE, ANTI-LOCK BRAKE SYSTEM (ABS), DESCRIPTION .
- Brake Lamp Sensor - The brake pedal position sensor is located on the brake pedal support bracket under the driver side of the instrument panel. Refer to SENSOR, STOP LAMP, DESCRIPTION .
- IPC - An indicator located in the IPC displays "CRUISE" to inform the vehicle operator when the speed control system is turned ON. Refer to DESCRIPTION .
- PCM - The 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 (PCM), 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.
- SCCM - A SCCM 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 (SCCM), 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 Local Interface Network (LIN) bus to the PCM, and by the PCM for control of the CRUISE indicator in the IPC. Refer to COMMUNICATION, DESCRIPTION .