Footnotes — Maintenance Schedule Additional Required Services — Severe

a) Or every two years, whichever comes first.

b) 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.

c) Or every four years, whichever comes first.

d) Do not directly power wash the transfer case output seals. High pressure water can overcome the seals and contaminate the transfer case fluid. Contaminated fluid will decrease the life of the transfer case and should be replaced.

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

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

    See also:

    How to Add Automatic Transmission Fluid
    Refer to the Maintenance Schedule to determine what kind of transmission fluid to use. See Recommended Fluids and Lubricants. If the fluid level is low, add only enough of the proper fluid to b ...

    Your Responsibility
    Increase the volume of the radio if the OnStar advisor cannot be heard. If the light next to the OnStar buttons is red, the system may not be functioning properly. Press and request a vehicle ...

    AM
    The range for most AM stations is greater than for FM, especially at night. The longer range can cause station frequencies to interfere with each other. For better radio reception, most AM r ...