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:

    If the Off Indicator is Lit for an Adult-Size Occupant
    If a person of adult-size is sitting in the right front passenger seat, but the off indicator is lit, it could be because that person is not sitting properly in the seat. If this happens, use the ...

    Diagnostics
    OnStar Vehicle Diagnostics will perform a vehicle check every month. It will check the engine, transmission, antilock brakes, and major vehicle systems. It also checks the tire pressures, if the vehic ...

    Engine Fan
    If the vehicle has a clutched engine cooling fan, when the clutch is engaged, the fan spins faster to provide more air to cool the engine. In most everyday driving conditions, the fan is spinning slo ...