Footnotes — Maintenance Schedule Additional Required Services — Severe

a) Check all fuel and vapor lines and hoses for proper hook-up, routing, and condition. Check that the purge valve, if the vehicle has one, works properly. Replace as needed.

b) Or every four years, whichever comes first.

c) Or every five years, whichever comes first. See Cooling System .

d) Or every 10 years, whichever comes first. Inspect for fraying, excessive cracking, or damage; replace, if needed.

    See also:

    Volume Control
    VOL/ (Volume/Power): Turn to adjust the volume. (Phone/Mute): For vehicles with OnStar®, press and hold to mute the infotainment system. Press and hold again, or turn the VOL/ knob t ...

    Cruise Control
    Cruise Control : Press to turn the cruise control system on and off. : Press to disengage cruise control without erasing the set speed from memory. RES/+: Move the thumbwheel up to ma ...

    Hill and Mountain Roads
    Driving on steep hills or through mountains is different than driving on flat or rolling terrain. Tips for driving in these conditions include: ► Keep the vehicle serviced and in good shape. ...