GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 1998 🢒 Safari - 2WD 🢒 Body and Accessories 🢒 Cruise Control 🢒 Cruise Control System Check

Use this procedure in order to test the operating modes of the cruise control system. Always use this procedure after you have completed repair work on the cruise system.

  1. Slide the multifunction lever/cruise switch to the ON position.
  2. Verify the correct operation of the Low Speed Inhibit function as follows:
    3. 2.1. Drive the vehicle at 32 km/h (20 mph).
    2.2. Depress the SET button, then release the button.
  3. If the system is operating properly, the cruise control will not engage.
  4. Verify the correct operation of the Set Speed function as follows:
    5. 4.1. Drive the vehicle at a steady speed of 89 km/h (55 mph).
    4.2. Depress the SET button completely, then release the button.
  5. If the system is operating properly, the cruise control will engage at approximately 89 km/h (55 mph).
  6. Verify the correct operation of the Brake Release function as follows:
    7. 6.1. Depress the brake pedal.
    6.2. Verify that the cruise control releases throttle, allowing the vehicle speed to drop.
    6.3. Release the brake.
    6.4. Verify that the cruise control system does not engage again.
  7. Verify the correct operation of the Resume function as follows:
    8. 7.1. While driving the vehicle at approximately 72 km/h (45 mph), momentarily slide the cruise switch to the RESUME/ACCEL position. Do not hold the switch in this position for more than 1 second before releasing it.
    7.2. Check the vehicle speed.
  8. If the system is operating properly, the vehicle should accelerate to approximately 89 km/h (55 mph).
  9. Verify the correct operation of the Coast function as follows:
    10. 9.1. Depress the SET button completely. Hold the button in the depressed position.
    9.2. Allow the vehicle speed to decrease to 80 km/h (50 mph), then release the SET button.
  10. If the system is operating properly, the cruise control should hold the vehicle speed at approximately 80 km/h (50 mph).
  11. Verify the correct operation of the Accelerate function as follows:
    12. 11.1. Slide the cruise control switch to the RESUME/ACCEL position. Hold the switch in this position.

    The vehicle speed should begin to increase.

    11.2. Allow the vehicle speed to increase to 89 km/h (55 mph).
    11.3. Release the RESUME/ACCEL switch.
  12. If the system is operating properly, the cruise control should hold the vehicle at approximately 89 km/h (55 mph).
  13. Verify the correct operation of the OFF switch as follows:
    14. 13.1. Turn the multifunction lever/cruise switch to the OFF position.
    13.2. Verify that the cruise control system disengages.