GMC 1999 Sierra 1500 Pickup Owner's Manual page 148

Features & Controls
that the pedal is harder to push. Or, the pedal may go closer to the floor.
It
may take longer to stop. If the light is still on, have the vehicle towed for
service. (See "Towing Your Vehicle" in the Index.)
CAUTION
*
Your brake system may not be working properly if the brake warning
light is on. Driving with the brake warning light on can lead to an
accident. If the light
is
still on after you've pulled off the road and
stopped carefully, have
+hq
vehicle towed for service.
"WATER IN FUEL" Light
WATER
IN
FUEL
I
-l
PB010
This light will come on to warn you if there is too much water in the diesel
fuel system. For more information on how this light works, see "Diesel Fuel
Requirements and Fuel System" in the Index.
2-80