Special Application Services

○ Severe Commercial Use Vehicles Only: Lubricate chassis components every 5 000 km/ 3,000 mi.
○ Have underbody flushing service performed once a year.

    See also:

    Engine Oil
    For diesel engine vehicles, see “Engine Oil” in the Duramax Diesel Supplement. To ensure proper engine performance and long life, careful attention must be paid to engine oil. Following these si ...

    Dual Tone Multi-Frequency (DTMF) Tones
    The Bluetooth system can send numbers and the numbers stored as name tags during a call. You can use this feature when calling a menu-driven phone system. Account numbers can also be stored for use. ...

    When to Inspect the Engine Air Cleaner/Filter
    Inspect or replace the air cleaner/ filter at the scheduled maintenance intervals. See Maintenance Schedule on page 11‑3 for more information. If driving in dusty/dirty conditions, inspect t ...