GM Service Manual Online
For 1990-2009 cars only

Cruise Control System Circuit Description V8 VIN G

The electro-motor cruise control is a speed control system that maintains a desired vehicle speed under normal driving conditions. The system has the capability to perform the following actions:

    • CRUISE
    • COAST
    • RESUME SPEED
    • ACCELERATE
    • TAP-UP
    • TAP-DOWN
    • CANCEL

The driver may cancel the cruise control by simultaneously depressing the following buttons:

    • SET
    • R/A

The cruise control module contains the following components:

    • An electronic controller
    • An electric motor

The controller performs the following operations:

    • Monitors vehicle speed
    • 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 action maintains the desired cruise speed. The cruise control module contains a low speed limit that will prevent system engagement below a minimum speed of approximately 25 mph. The module is controlled by mode control switches. The mode control switches are located on the multi-function lever. Cruise control operation requires that the operator set an initial speed using the SET/COAST button before the RESUME/ACCEL function is active.

Battery voltage is applied to terminal F of the cruise control module when the ignition switch is in the RUN position. When the slider switch is moved to the ON position, battery voltage is applied to terminal A of the cruise control module. The cruise control module needs to receive brake input voltage at one of the following terminals once each ignition cycle before allowing cruise to operate:

    • Terminal D
    • Terminal G

The brake input voltage is received at the cruise control module through the following components:

  1. The A/C CRUISE Fuse 12
  2. The cruise control release brake switch
  3. The cruise control clutch switch on vehicles equipped with a manual transmission

The voltage to the cruise control module terminal D is interrupted if either of the above switches is open. Terminal G must see a ground path through the CHMSL bulb in order for the cruise to operate properly. If the brake pedal is depressed, battery voltage is present at the module terminal G. When the slider switch is moved to the RESUME/ACCEL position, battery voltage is applied to terminal C of the module. With the set switch depressed, battery voltage is present at cruise module terminal B. Cruise module connector terminal K is the speed signal terminal. During operation the voltage will oscillate between the following levels:

    • A high of 4 to 5 volts
    • A low of near ground

The cruise module ground is at module terminal E.

Cruise Control System Circuit Description V6 VIN K

For V8 VIN G vehicles refer to Cruise Control System Circuit Description .

The electro-motor cruise control is a speed control system that maintains a desired vehicle speed under normal driving conditions. The system has the capability to perform the following actions:

    • CRUISE
    • COAST
    • RESUME SPEED
    • ACCELERATE
    • TAP-UP
    • TAP-DOWN
    • CANCEL

The driver may cancel the cruise control by simultaneously depressing the following buttons:

    • SET
    • R/A

The cruise control module contains the following components:

    • An electronic controller
    • An electric motor

The controller performs the following operations:

    • Monitors vehicle speed
    • 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 action maintains the desired cruise speed. The cruise control module contains a low speed limit that will prevent system engagement below a minimum speed of approximately 25 mph. The module is controlled by mode control switches. The mode control switches are located on the multi-function lever. Cruise control is in Standby Disabled until all the conditions inconsistent with cruise control operation are cleared.

Battery voltage is applied to terminal F of the cruise control module when the ignition switch is in the RUN position. When the slider switch is moved to the ON position, battery voltage is applied to terminal A of the cruise control module. The cruise control module needs to receive brake input voltage at one of the following terminals once each ignition cycle before allowing cruise to operate:

    • Terminal D
    • Terminal G

Terminal G must see a ground path through the CHMSL bulb in order for the cruise to operate properly. If the brake pedal is depressed, battery voltage is present at the module terminal G. When the slider switch is moved to the RESUME/ACCEL position, battery voltage is applied to terminal C of the module. With the set switch depressed, battery voltage is present at cruise module terminal B. Cruise module connector terminal K is the speed signal terminal. During operation the voltage will oscillate between the following levels:

    • A high of 4 to 5 volts
    • A low of near ground

The cruise module ground is at module terminal E. Terminal J is used to signal the powertrain control module (PCM) when cruise control is engaged. The PCM determines the correct shift pattern for the transmission. Terminal H is used by the PCM in order to inhibit cruise control when the conditions are not consistent with cruise operation are present. The following lists the cruise control inhibit criteria:

    • The vehicle speed sensor (VSS) is less than 25 mph.
    • The PARK, REVERSE, NEUTRAL or 1st GEAR is indicated by the transaxle range switch.
    • An over/under battery voltage condition exists.
    • The engine RPM is low.
    • The engine RPM is high (fuel cutoff).