GMC 2003 Envoy - Manual (Page 410)

100,000 Miles (1G€ 000 km)
J Vfi En^lriE Onl/; Inspecl spark pJyg wFres.
An Emission Control Servico.
Zi Rapiate spark plugs. An Emission Control Servico.
D Change automalic transmisslnn fluid and Filter if the
vehicle is mainly driven under one or more of these
conditions;
- in heavy city traffic whers the outside
temperaiore regularly reaches 90'^F [32"C)
or higher.
- In hilly ormounlflinous terrairt.
- When doing trequeni tra iter towing.
- Uses $uch as found in taxi, police or delivery
service.
□ It you havert't used your vehicle under severs service
condilions fisted previously end, ttierelcre, haven't
changed your automatic tra ns mission fluids change
bolh the fluid snd filter
□ Automatic Transfer Case Only: Change transfer
case fluid г
□ VS Engine Only: Inspect Positive Crankcase
Ventilatiori (PCV) valve. An Emission Сол1ла^ Service.
150,000 Miles (240 000 km)
J Drain, flush and refill cooling system (or every
eo months slnc 0 last service, whichever occurs first).
See Engine Cooient on pnge 5-2^ lor what to use
InspecI hoses. Clean radiator, condenser, pressure
cap and necii. Pressure test the cooling system
and pressure cap.
An Emission Cantrai SenriCB.
■J Inspect engine accessory drive bell. An Emission
Control Service.
6'9