Pontiac 2001 Firebird Owner's Manual page 273

Wait at least 30 minutes before checking the
transmission fluid level if you have been driving:
D
When outside temperatures are above 90
D
At high speed for quite a while.
D
--
In heavy traffic especially in hot weather.
D
While pulling a trailer.
To get the right reading, the fluid should be at normal
operating temperature, which is 180
_ _
(82 C to 93 C).
Get the vehicle warmed up by driving about 15 miles
(24 km) when outside temperatures are above 50
_
(10 C). If it's colder than 50
vehicle in DRIVE (D) 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.
_ _
F (32 C).
_ _
F to 200 F
_
F
_ _
F (10 C), drive the
Let the engine run at idle for five minutes if outside
_
temperatures are 50 F (10
_ _
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.
Checking the Fluid Level
Prepare your vehicle as follows:
D
Park your vehicle on a level place. Keep the
engine running.
D
With the parking brake applied, place the shift lever
in PARK (P).
D
With your foot on the brake pedal, move the shift
lever through each gear range, pausing for about
three seconds in each range. Then, position the
shift lever in PARK (P).
D
Let the engine run at idle for three minutes or more.
_
C) or more. If it's colder
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