GMC 1994 Sonoma Owner's Manual page 304

6.
7.
8.
9.
10.
TRANSMISSION SERVICE:
Automatic Transmission
-
Change the transmission fluid and filter
every 15,000 miles (25 000
k m )
if the vehicle is mainly driven under
one or more of these conditions:
0
e
0
e
0
In heavy city traffic.
Where the outside temperature regularly reaches 90°F (32°C) or
higher.
In hilly or mountainous terrain.
Frequent trailer pulling.
Uses such as taxi, police, delivery or other commercial service.
If the vehicle is not used mainly under any of these conditions, change
the fluid and filter every 30,000 miles (50 000
km).
See "Automatic
Transmission Fluid" in the Index for more information.
Manual Transmission - Transmission fluid does not require periodic
changing.
FUEL FILTER REPLACEMENT*
-
Replace the fuel filter at the
specified interval or sooner if clogged.
SPARK PLUG REPLACEMENT*$
-
Replace spark plugs with the
type listed in Section 6. Spark plugs (AC908) for the 2.2L Engine (VIN
Code 4) should be replaced every 100,000 miles (1 66 000 kilometers).
Spark plugs (.CR43TSM) for the 4.3L engines (VIN Codes W and Z)
should be replaced every 30,000 miles (50 000 kilometers). See
"Specification Charts" in the Index.
SPARK PLUG WIRE INSPECTION* - Clean wires and inspect
for burns, cracks or other damage. Check the wire boot fit at the
distributor and at the spark plugs. Replace wires as needed.
ENGINE TIMING CHECK AND DISTRIBUTOR CHECK*$
-
Adjust timing to underhood label specifications. Inspect the inside and
outside of the distributor cap and rotor for cracks, carbon tracking and
corrosion. Clean or replace as needed.
*An Emission Control Service
$=The California Air Resources Board has determined that the failure to
perform this maintenance item will not nullify the emission warranty or
limit recall liability prior to the completion of vehicle useful life. General
Motors, however, urges that all recommended maintenance services be
performed at the indicated intervals and the maintenance be recorded.
7-8