The Stepper Motor Cruise Control (SMCC) is a speed control system which maintains a desired vehicle speed under normal driving conditions. However, steep grades up or down may cause variations in the selected speeds. The system has the following capabilities:

An electronic controller and electric motor are contained in the cruise control module. The controller monitors the vehicle speed and operates the electric motor. In response to the controller, the motor moves a connecting strap that is attached to the cruise control cable. The cable moves the throttle linkage in order to vary the throttle position. This maintains the desired cruise speed. The cruise control module contains a low speed limit which prevents system engagement below a minimum speed, approximately 40 km/h (25 mph). The module is controlled by mode control switches which are located on the cruise control switch. Cruise control is in standby disabled mode until all conditions which are inconsistent with cruise control operation are cleared.

Ignition voltage is supplied from the CRUISE fuse, through circuit 341 to terminal F of the cruise control module. The cruise control module receives ground at terminal E, through circuit 1750, and from G201. When the cruise control switch is on, battery voltage is applied through circuit 397 to terminal A of the cruise control module connector.

If the brake pedal is not pressed, battery voltage is present from circuit 986 through the cruise control release switch, to circuit 86, and to the cruise control module terminal D. If the brake pedal is pressed, battery voltage is supplied from the STOPLAMP fuse, through circuit 140, the stoplamp switch and circuit 17 to the cruise control module terminal G. Terminal G must detect current flow through the Center High-Mounted Stoplamp (CHMSL) bulbs for the cruise control to operate properly.

When pressing Resume/Accelerate (R/A) on the steering wheel control switch, battery voltage is applied through circuit 87 to terminal C of the cruise control module. When pressing Set/Coast on the steering wheel control switch, battery voltage is present through circuit 84 to the cruise control module terminal B.

The clear switch is closed under normal operating procedures. When the clear switch opens, the 12V signal through circuit 986 to the cruise control release switch disengages.

The cruise control module terminal K is the vehicle speed signal input terminal through circuit 817. In operation, the voltage varies between 0V and 5V. The cruise control module terminal J is used to signal the Powertrain Control Module (PCM) when cruise control is engaged through circuit 85. The PCM will then determine the correct shift pattern for the transmission. The cruise control module terminal H is used by the PCM through circuit 83, in order to inhibit cruise control when conditions inconsistent with cruise operation are present.

The PCM will inhibit cruise control under the following conditions: