GM Service Manual Online
For 1990-2009 cars only

The stepper motor cruise control is a speed control system which maintains a desired speed under normal driving conditions. The system has the following functions:

    • Cruise
    • Coast
    • Resume speed
    • Accelerate
    • Tap-up
    • Tap-down

The cruise control module contains the following components:

    • The electronic controller
    • The electric motor

The electronic controller monitors the vehicle speed. The electronic controller operates the electric motor. The motor moves a connecting strap attached to the cruise control cable in response to the electronic controller. The cable moves the throttle linkage in order to vary the throttle position. The throttle position varies in order to maintain the desirable cruise speed.

The cruise control module contains a low speed limit. The low speed limit will prevent the engagement below a minimum speed. The minimum speed is approximately 25 mph (40 Km/h). The cruise control is in the standby disabled mode until all of the conditions that are inconsistent with the cruise control operations clear. Battery voltage applies to terminal F of the cruise control module when the ignition switch is in the RUN position. Moving the slider switch to the ON position applies the battery voltage to terminal A of the cruise control module to initialize this process.

Battery voltage is present at module terminal D (allow engagement) if the brake pedal is in the at-rest position. The at-rest position is when the brakes are not applied. Applying the brake pedal presents the battery voltage at the module terminal G (disengage/do not allow engagement). The 510ohmsCHMSL resistor is used for the pull down of the cruise control circuit. Moving the slider switch to the RESUME/ACCEL position applies the battery voltage to terminal C of the cruise control module. Moving the slide switch to the SET/COAST position applies the battery voltage to terminal B of the cruise control module. While the Cruise Control is engaged and the vehicle speed is between 25 MPH and 85 MPH, vehicle speed can be increased by tapping on the RESUME/ACCEL switch or decreased by tapping on the SET/COAST switch. Ground is at terminal E of the cruise control module. The vehicle control module uses terminal J in order to send a signal when the cruise control engages.