GMC 2012 Canyon Owner's Manual page 257

A good time to check the automatic
transmission fluid level is when the
engine oil is changed.
Change the fluid and filter at the
intervals listed in
, and be sure
to use the transmission fluid listed in
Because this operation can be a
little difficult, it may be decided to
have this done at the dealer service
department.
If not taken to the dealer, be sure
to follow all the instructions here,
or a false reading on the dipstick
could result.
Wait at least 30 minutes before
checking the transmission fluid level
if the vehicle has been driven:
.
When outside temperatures are
above 32°C (90°F).
At high speed for quite a while.
In heavy traffic
hot weather.
While pulling a trailer.
To get the right reading, the fluid
should be at normal operating
temperature, which is 82°C to 93°C
(180°F to 200°F).
Get the vehicle warmed up by
driving about 24 km (15 mi) when
outside temperatures are above
10°C (50°F). If it is colder than 10°C
(50°F), drive the vehicle in 3 (Third)
until the engine temperature gauge
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 10°C (50°F) or
more. If it is colder than 10°C
(50°F), the engine may have to idle
longer. Should the fluid level be low
during this cold check, check the
especially in
fluid hot before adding fluid.
Checking the fluid hot gives a more
accurate reading of the fluid level.