GMC 2009 Savana - Manual (Page 264)

How to Check Automatic
Transmission Fluid
Because this operation can be a little difficult, you may
choose to have this done at the dealer/retailer service
department.
If you do it yourself, be sure to follow all the instructions
here, or you could get a false reading on the dipstick.
Notice: Too much or too little fluid can damage
your transmission. Too much can mean that some
of the fluid could come out and fall on hot engine
parts or exhaust system parts, starting a fire.
Too little fluid could cause the transmission to
overheat. Be sure to get an accurate reading if
you check your transmission fluid.
Wait at least 30 minutes before checking the
transmission fluid level if you have been driving:
• When outside temperatures are above 90°F (32°C).
• At high speed for quite a while.
• In heavy traffic — especially in hot weather.
• While pulling a trailer.
To get the right reading, the fluid should be at normal
operating temperature, which is 180°F to 200°F
(82°C to 93°C).
Get the vehicle warmed up by driving about
15 miles (24 km) when outside temperatures are
above 50°F (10°C). If it is colder than 50°F (10°C), drive
the vehicle in D (DRIVE) until the engine temperature
gage moves and then remains steady for 10 minutes.
A cold fluid check can be made after the vehicle has
been sitting for eight hours or more with the engine off,
but this is used only as a reference. Let the engine run
at idle for five minutes if outside temperatures are 50°F
(10°C) or more. If it is colder than 50°F (10°C), you may
have to idle the engine longer. Should the fluid level be
low during this cold check, you must check the fluid hot
before adding fluid. Checking the fluid hot will give you a
more accurate reading of the fluid level.
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