GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 1999 🢒 Chevy K Silverado - 4WD 🢒 Body and Accessories 🢒 Cruise Control 🢒 Cruise Control System Description

Cruise Control System Description Gasoline

  1. The cruise control system associated with gasoline engines includes the following components:
    2. • The vehicle control module (VCM) 4.3L
    • The powertrain control module (PCM) all other engines.
    • The cruise control module
    • The multifunction lever
    • The brake release switch
  2. The cruise control module operates in the following manner:
    3. 2.1. The cruise control module contains a stepper motor.

    The stepper motor is used to change throttle position.

    2.2. The cruise control module receives commands from the multifunction lever.
    2.3. The cruise control module receives vehicle speed from the VCM or PCM.
    2.4. The cruise control module uses the multifunction lever and the VCM or the PCM in order to control speed.

Brake Release Switch

The cruise control module uses an electronic brake switch which contains 1 normally open switch contact and 1 normally closed switch contact. These contacts are part of the brake switch.

When the brake pedal is depressed, the 2 brake switch contacts change input states at the cruise control module. The cruise control module then shuts off all the cruise control outputs.

Clutch Release Switch

For vehicles equipped with a manual transmission, the clutch release switch is on the clutch push-rod. When the clutch pedal is depressed, the clutch release switch activates and interrupts the voltage supply to the cruise control circuit in the engine control module. The clutch release switch disengages the cruise module.

Vehicle Speed Signal

The vehicle speed sensor (VSS) generates the vehicle speed signal at the transmission. The VCM or PCM translates the VSS signal.

The VSS mounts to the automatic transmission assembly. The VSS produces an AC signal. The frequency of this signal is proportionate to the transmission output shaft speed. The AC signal is sent to the VCM or the PCM for amplification and conversion to a digital square wave that represents the vehicle speed in terms of pulses per mile (ppm). The VCM or the PCM provides a 4000 PPM signal.

This 4000 PPM signal is available to the cruise control module and the speedometer in the instrument cluster.