GMC 2005 T-Series Owner's Manual page 159

Water In Fuel Light Chart
Problem
Light comes on
intermittently.
Light stays on at
temperatures above
freezing.
Light stays on at
temperatures below
freezing.
Light stays on
immediately after
refueling, and a large
amount of water was
possibly pumped into the
fuel tank.
Recommended Action
Drain water from the fuel
filter.
Drain the fuel filter
immediately. If no water
can be drained and the
light stays on, see your
dealer for assistance.
Drain the fuel filter
immediately. If no water
can be drained, water
may be frozen in the
water drain system or in
the fuel lines. Move the
vehicle to a warm location
to thaw out, and then
drain the filter system.
Fuel tank purging is
required. See your dealer
for assistance.
Notice: If you drive when this warning indicator is
on, you can damage your fuel injection system
and your engine. If the indicator comes on right after
you refuel, it means water was pumped into your
fuel tank. Turn off your engine immediately.
Then, have the water drained at once.
The frequency of water draining or element replacement
is determined by the contamination level in the fuel.
Inspect or service the collection bowl for water daily and
replace the element as shown in the Maintenance
Schedule. See Scheduled Maintenance on page 6-5 for
change interval information.
To drain water, do the following:
2. Tighten the drain. Run the engine and check
for leaks.
1. Loosen the self-venting
drain to empty the bowl
of water.
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