How to Check Lubricant
To get an accurate reading, the vehicle should be on a level surface.

1500 Series
A. Fill Plug
B. Drain Plug

All Except 1500 Series
A. Fill Plug
B. Drain Plug
• When the differential is cold, add enough lubricant to raise the level from 0mm (0 in) to 3.2mm (1/8 in) below the fill plug hole.
• When the differential is at operating temperature (warm), add enough lubricant to raise the level to the bottom of the fill plug hole.
See also:
When Using the Manual Transfer Case
• Shifts into or out of Four-Wheel Drive Low or N (Neutral) should be made using quick motions to avoid excessive gear grinding.
Shifting slowly may make it more difficult to shift.
• You may no ...
Service Vehicle Messages
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This message displays when the electronic sensors that control the air conditioning and heating systems are no longer working.
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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
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