Electronic cruise control is a speed control system. The system maintains a desired vehicle speed under normal driving conditions. However, steep grades may cause variation in the selected speeds. The electronic cruise control system has the capability to perform the following functions:

The cruise control system includes the following main components:

The cruise control system uses a cruise control module assembly in order to obtain the desired vehicle cruise operation. The following 2 components in the module are primarily responsible for this operation:

The electronic controller monitors the vehicle speed. The controller operates the electric stepper motor. The motor moves a band and throttle linkage in response to the controller in order to maintain the desired cruise speed. A low speed limit feature in the cruise control module assembly prevents system engagement below a minimum of 40 km/h (25 mph). Functional switches on the multi-function turn signal lever operate the controller.

The cruise control release switch assembly and the stoplamp switch assembly disengage the cruise control system. These switch assemblies are mounted on the brake pedal bracket assembly. When the brake pedal assembly is depressed, the cruise control system electronically disengages. The throttle returns to the idle position. The system disengages by the activation of the brake cut-out input to the cruise control module assembly. When the brakes are applied, the system memory stores the speed of the vehicle.

The vehicle speed sensor (VSS) is mounted on the transmission assembly. The VSS produces an AC signal. The frequency of the signal is proportional to the rotational speed of the transmission assembly output shaft. The rotational speed is proportional to the speed of the vehicle.

The VSS buffer amplifies and converts the AC signal which the VSS produces. The VSS buffer assembly supplies the signal to the following components:

The VSS buffer opens and closes internal solid state switches to ground in order to produce the signal. The PCM converts the signal to 4000 pulses per mile.

The signal reaches the cruise control module and the speedometer assembly at a rate of 4000 pulses per mile. The control module and speedometer assembly internally convert the number of pulses per mile to pulses per second in order to determine vehicle speed.

Vehicle Speed Sensor Buffer Assembly

The VSS buffer assembly receives a signal from the VSS (permanent magnet generator). The signal indicates the speed of the vehicle. The VSS buffer assembly processes this signal and supplies the signal to the following: