GMC 1996 Sonoma Owner's Manual page 338

Long
Tripmighway daintenance Schedule
100,000 Miles (I 66 000 km) (Continued)
c] Change automatic transmission fluid and
filter if the vehicle is mainly driven under
one or more of these conditions:
-
In heavy city traffic where the outside
temperature regularly reaches 90 O F
(32°C) or higher.
-
In hilly or mountainous terrain.
-
When doing frequent trailer towing.
-
Uses such as found in taxi, police or
delivery service.
I f
you
do rzot
L L S ~
your vehicle m d e r any o f
these conditiom, thecfluid m d f i l t e r do n.ot
m p i r e changing.
Manual transmission fluid doesn't require change.
0
Inspect Positive Crankcase Ventilation
(PCV) valve.
An Emission Colltrol %]-vice.
7-46