cooling GMC SIERRA 2009 User Guide

Hill and Mountain Roads
Driving on steep hills or through mountains is different
than driving on at or rolling terrain. Tips for driving
in these conditions include:
Keep the vehicle serviced and in good shape.
Check all uid levels and brakes, tires, cooling
system, and transmission.
Going down steep or long hills, shift to a lower gear.
{CAUTION:
If you do not shift down, the brakes could get so
hot that they would not work well. You would then
have poor braking or even none going down a hill.
You could crash. Shift down to let the engine
assist the brakes on a steep downhill slope.
{CAUTION:
Coasting downhill in N (Neutral) or with the ignition
off is dangerous. The brakes will have to do all the
work of slowing down and they could get so hot
that they would not work well. You would then
have poor braking or even none going down a hill.
You could crash. Always have the engine running
and the vehicle in gear when going downhill.
Stay in your own lane. Do not swing wide or cut
across the center of the road. Drive at speeds
that let you stay in your own lane.
Top of hills: Be alert — something could be in your
lane (stalled car, accident).
Pay attention to special road signs (falling rocks
area, winding roads, long grades, passing or
no-passing zones) and take appropriate action.
SeeOff-Road Driving on page 4-12for information
about driving off-road.
4-27

Vehicle Axle Ratio Maximum Trailer Weight GCWR (a)
1500 Series 2WD Regular Cab Standard Box (b)
4.3L V6 (c) 3.23 4,800 lbs (2 177 kg) 9,500 lbs (4 309 kg)
4.3L V6 (c) 3.73 5,300 lbs (2 404 kg) 10,000 lbs (4 536 kg)
4.8L V8 (c) 3.23 5,200 lbs (2 359 kg) 10,000 lbs (4 536 kg)
4.8L V8 3.73 7,200 lbs (3 266 kg) 12,000 lbs (5 443 kg)
5.3L V8 4 Speed Automatic 3.42 7,200 lbs (3 266 kg) 12,000 lbs (5 443 kg)
5.3L V8 4 Speed Automatic 3.73 8,200 lbs (3 720 kg) 13,000 lbs (5 897 kg)
5.3L LMG V8 6 Speed Automatic 3.42 6,600 lbs (2 994 kg) 11,500 lbs (5 216 kg)
5.3L LY5 V8 6 Speed Automatic 3.42 6,700 lbs (3 039 kg) 11,500 lbs (5 216 kg)
5.3L LMG V8 6 Speed Automatic,
K5L HD Cooling Pkg3.42 9,100 lbs (4 128 kg) 14,000 lbs (6 350 kg)
5.3L LY5 V8 6 Speed Automatic,
K5L HD Cooling Pkg3.42 9,200 lbs (4 173 kg) 14,000 lbs (6 350 kg)
1500 Series 2WD Extended Cab Standard Box (b)
4.3L V6 (c) 3.23 4,400 lbs (1 996 kg) 9,500 lbs (4 309 kg)
4.3L V6 (c) 3.73 4,900 lbs (2 223 kg) 10,000 lbs (4 536 kg)
4.8L V8 (c) 3.23 4,700 lbs (2 132 kg) 10,000 lbs (4 536 kg)
4.8L V8 3.73 6,700 lbs (3 039 kg) 12,000 lbs (5 443 kg)
4-53

Vehicle Axle Ratio Maximum Trailer Weight GCWR (a)
5.3L V8 4 Speed Automatic 3.42 6,700 lbs (3 039 kg) 12,000 lbs (5 443 kg)
5.3L V8 4 Speed Automatic 3.73 7,700 lbs (3 493 kg) 13,000 lbs (5 897 kg)
5.3L V8 6 Speed Automatic 3.42 6,200 lbs (2 812 kg) 11,500 lbs (5 216 kg)
5.3L V8 6 Speed Automatic, K5L HD
Cooling Pkg — Fifth-Wheel Trailer3.42 9,100 lbs (4 128 kg) 15,000 lbs (6 804 kg)
5.3L V8 6 Speed Automatic, K5L HD
Cooling Pkg — Conventional Trailer3.42 9,700 lbs (4 400 kg) 15,000 lbs (6 804 kg)
6.0L V8 3.42 6,700 lbs (3 039 kg) 12,000 lbs (5 443 kg)
6.0L V8 K5L HD Cooling
Pkg — Fifth-Wheel Trailer3.42 8,700 lbs (3 946 kg) 15,000 lbs (6 804 kg)
6.0L V8 K5L HD Cooling
Pkg — Conventional Trailer3.42 9,700 lbs (4 400 kg) 15,000 lbs (6 804 kg)
6.0L V8 NHT Max Trailering
Pkg — Fifth-Wheel Trailer3.73 10,000 lbs (4 536 kg) 16,000 lbs (7 257 kg)
6.0L V8 NHT Max Trailering
Pkg — Conventional Trailer3.73 10,700 lbs (4 853 kg) 16,000 lbs (7 257 kg)
1500 Series 2WD Extended Cab Short Box (c)
4.3L V6 3.23 4,400 lbs (1 996 kg) 9,500 lbs (4 309 kg)
4.3L V6 3.73 4,900 lbs (2 223 kg) 10,000 lbs (4 536 kg)
4.8L V8 3.42 5,800 lbs (2 631 kg) 12,000 lbs (5 443 kg)
4-54

Vehicle Axle Ratio Maximum Trailer Weight GCWR (a)
4.8L V8 3.73 6,800 lbs (3 084 kg) 12,000 lbs (5 443 kg)
5.3L V8 3.42 6,800 lbs (3 084 kg) 12,000 lbs (5 443 kg)
5.3L V8 3.73 7,800 lbs (3 538 kg) 13,000 lbs (5 897 kg)
6.0L V8 3.42 6,700 lbs (3 039 kg) 12,000 lbs (5 443 kg)
6.0L V8 K5L HD Cooling Pkg 3.42 9,700 lbs (4 400 kg) 15,000 lbs (6 804 kg)
1500 Series 2WD Crew Cab Short Box (c)
4.8L V8 3.23 4,700 lbs (2 132 kg) 10,000 lbs (4 536 kg)
4.8L V8 3.73 6,700 lbs (3 039 kg) 12,000 lbs (5 443 kg)
5.3L V8 3.42 6,100 lbs (2 767 kg) 11,500 lbs (5 216 kg)
5.3L V8 K5L HD Cooling Pkg 3.42 9,600 lbs (4 355 kg) 15,000 lbs (6 804 kg)
6.0L, 6.2L V8 3.42 6,600 lbs (2 994 kg) 12,000 lbs (5 443 kg)
6.0L, 6.2L V8 K5L HD Cooling Pkg 3.42 9,600 lbs (4 355 kg) 15,000 lbs (6 804 kg)
6.0L, 6.2L V8 NHT Max
Trailering Pkg3.73 10,600 lbs (4 808 kg) 16,000 lbs (7 257 kg)
1500 Series 2WD Regular Cab Long Box (b)
4.3L V6 (c) 3.23 4,700 lbs (2 132 kg) 9,500 lbs (4 309 kg)
4.3L V6 (c) 3.73 5,200 lbs (2 359 kg) 10,000 lbs (4 536 kg)
4.8L V8 (c) 3.23 5,100 lbs (2 313 kg) 10,000 lbs (4 536 kg)
4-55

Vehicle Axle Ratio Maximum Trailer Weight GCWR (a)
4.8L V8 3.73 7,100 lbs (3 221 kg) 12,000 lbs (5 443 kg)
5.3L V8 4 Speed Automatic 3.42 7,000 lbs (3 175 kg) 12,000 lbs (5 443 kg)
5.3L V8 4 Speed Automatic 3.73 8,000 lbs (3 629 kg) 13,000 lbs (5 897 kg)
5.3L V8 6 Speed Automatic 3.42 6,500 lbs (2 948 kg) 11,500 lbs (5 216 kg)
5.3L V8 6 Speed Automatic, K5L HD
Cooling Pkg — Fifth-Wheel Trailer3.42 8,700 lbs (3 946 kg) 15,000 lbs (6 804kg)
5.3L V8 6 Speed Automatic, K5L HD
Cooling Pkg — Conventional Trailer3.42 10,000 lbs (4 536 kg) 15,000 lbs (6 804kg)
1500 Series 2WD Extended Cab Long Box (b)
5.3L V8 4 Speed
Automatic — Fifth-Wheel Trailer3.73 7,500 lbs (3 402 kg) 13,000 lbs (5 897 kg)
5.3L V8 4 Speed
Automatic — Conventional Trailer3.73 7,600 lbs (3 447 kg) 13,000 lbs (5 897 kg)
5.3L V8 6 Speed Automatic 3.42 6,000 lbs (2 722 kg) 11,500 lbs (5 216 kg)
5.3L V8 6 Speed Automatic, K5L HD
Cooling Pkg — Fifth-Wheel Trailer3.42 8,700 lbs (3 946 kg) 15,000 lbs (6 804kg)
5.3L V8 6 Speed Automatic, K5L HD
Cooling Pkg — Conventional Trailer3.42 9,500 lbs (4 309 kg) 15,000 lbs (6 804kg)
4-56

Vehicle Axle Ratio Maximum Trailer Weight GCWR (a)
1500 Series 4WD Regular Cab Standard Box (b)
4.3L V6 (c) 3.73 5,100 lbs (2 313 kg) 10,000 lbs (4 536 kg)
4.8L V8 (c) 3.42 6,000 lbs (2 722 kg) 11,000 lbs (4 990 kg)
5.3L V8 3.42 6,400 lbs (2 903 kg) 11,500 lbs (5 216 kg)
5.3L V8 K5L HD Cooling
Pkg — Fifth-Wheel Trailer3.42 8,100 lbs (3 674 kg) 14,000 lbs (6 350 kg)
5.3L V8 K5L HD Cooling
Pkg — Conventional Trailer3.42 8,900 lbs (4 037 kg) 14,000 lbs (6 350 kg)
5.3L V8 3.73 7,900 lbs (3 583 kg) 13,000 lbs (5 897 kg)
5.3L V8 — Fifth-Wheel Trailer 4.10 8,300 lbs (3 765 kg) 14,000 lbs (6 350 kg)
5.3L V8 — Conventional Trailer 4.10 8,900 lbs (4 037 kg) 14,000 lbs (6 350 kg)
1500 Series 4WD Extended Cab Standard Box (b)
4.8L V8 (c) 3.42 5,500 lbs (2 495 kg) 11,000 lbs (4 990 kg)
5.3L V8 (c) 3.42 5,900 lbs (2 676 kg) 11,500 lbs (5 216 kg)
5.3L V8 K5L HD Cooling
Pkg — Fifth-Wheel Trailer3.42 8,900 lbs (4 037 kg) 15,000 lbs (6 804kg)
5.3L V8 K5L HD Cooling
Pkg — Conventional Trailer3.42 9,400 lbs (4 264 kg) 15,000 lbs (6 804kg)
5.3L V8 3.73 7,500 lbs (3 402 kg) 13,000 lbs (5 897 kg)
4-57

Vehicle Axle Ratio Maximum Trailer Weight GCWR (a)
5.3L V8 4.10 8,500 lbs (3 856 kg) 14,000 lbs (6 350 kg)
6.0L V8 (c) 3.42 6,400 lbs (2 903 kg) 12,000 lbs (5 443 kg)
6.0L V8 K5L HD Cooling
Pkg — Fifth-Wheel Trailer3.42 8,400 lbs (3 810 kg) 15,000 lbs (6 804kg)
6.0L V8 K5L HD Cooling
Pkg — Conventional Trailer3.42 9,400 lbs (4 264 kg) 15,000 lbs (6 804kg)
6.0L V8 NHT Max Trailering
Pkg — Fifth-Wheel Trailer3.73 9,700 lbs (4 400 kg) 16,000 lbs (7 257 kg)
6.0L V8 NHT Max Trailering
Pkg — Conventional Trailer3.73 10,400 lbs (4 717 kg) 16,000 lbs (7 257 kg)
1500 Series 4WD Extended Cab Short Box (c)
4.8L V8 3.42 5,500 lbs (2 495 kg) 11,000 lbs (4 990 kg)
4.8L V8 4.10 8,500 lbs (3 856 kg) 14,000 lbs (6 350 kg)
5.3L V8 3.73 7,500 lbs (3 402 kg) 13,000 lbs (5 897 kg)
5.3L V8 4.10 8,500 lbs (3 856 kg) 14,000 lbs (6 350 kg)
6.0L V8 3.42 6,400 lbs (2 903 kg) 12,000 lbs (5 443 kg)
6.0L V8 K5L HD Cooling Pkg 3.42 9,400 lbs (4 264 kg) 15,000 lbs (6 804kg)
4-58

Vehicle Axle Ratio Maximum Trailer Weight GCWR (a)
1500 Series 4WD Crew Cab Short Box (c)
4.8L V8 3.42 5,400 lbs (2 449 kg) 11,000 lbs (4 990 kg)
5.3L V8 3.42 6,000 lbs (2 722 kg) 11,500 lbs (5 216 kg)
5.3L V8 K5L HD Cooling Pkg 3.42 9,500 lbs (4 309 kg) 15,000 lbs (6 804kg)
6.0L, 6.2L V8 3.42 6,300 lbs (2 858 kg) 12,000 lbs (5 443 kg)
6.0L, 6.2L V8 K5L HD Cooling Pkg 3.42 9,300 lbs (4 218 kg) 15,000 lbs (6 804kg)
6.0L V8 NHT Max Trailering
Pkg — Fifth-Wheel Trailer3.73 9,900 lbs (4 491 kg) 16,000 lbs (7 257 kg)
6.0L, 6.2L V8 NHT Max Trailering
Pkg — Conventional Trailer3.73 10,400 lbs (4 717 kg) 16,000 lbs (7 257 kg)
1500 Series 4WD Regular Cab Long Box (b)
4.3L V6 (c) 3.73 4,900 lbs (2 223 kg) 10,000 lbs (4 536 kg)
4.8L V8 (c) 3.42 5,800 lbs (2 631 kg) 11,000 lbs (4 990 kg)
5.3L V8 3.42 6,300 lbs (2 858 kg) 11,500 lbs (5 216 kg)
5.3L V8 K5L HD Cooling
Pkg — Fifth-Wheel Trailer3.42 9,500 lbs (4 309 kg) 15,000 lbs (6 804kg)
5.3L V8 K5L HD Cooling
Pkg — Conventional Trailer3.42 9,800 lbs (4 445 kg) 15,000 lbs (6 804kg)
5.3L V8 — Fifth-Wheel Trailer 3.73 7,800 lbs (3 538 kg) 13,000 lbs (5 897 kg)
4-59

Vehicle Axle Ratio Maximum Trailer Weight GCWR (a)
5.3L V8 — Conventional Trailer 3.73 7,900 lbs (3 583 kg) 13,000 lbs (5 897 kg)
5.3L V8 — Fifth-Wheel Trailer 4.10 8,800 lbs (3 992 kg) 14,000 lbs (6 350 kg)
5.3L V8 — Conventional Trailer 4.10 8,900 lbs (4 037 kg) 14,000 lbs (6 350 kg)
1500 Series 4WD Extended Cab Long Box (b)
5.3L V8 (c) 3.42 5,700 lbs (2 586 kg) 11,500 lbs (5 216 kg)
5.3L V8 K5L HD Cooling
Pkg — Fifth-Wheel Trailer3.42 7,700 lbs (3 493 kg) 15,000 lbs (6 804 kg)
5.3L V8 K5L HD Cooling
Pkg — Conventional Trailer3.42 9,200 lbs (4 173 kg) 15,000 lbs (6 804 kg)
5.3L LMG V8 3.73 7,600 lbs (3 447 kg) 13,000 lbs (5 897 kg)
5.3L LY5 V8 3.73 7,300 lbs (3 311 kg) 13,000 lbs (5 897 kg)
2500 Series 2WD Extended Cab Standard Box HD (d)
6.0L V83.73
4.1010,200 lbs (4 627 kg)
12,700 lbs (5 761 kg)16,000 lbs (7 257 kg)
18,500 lbs (8 391 kg)
2500 Series 2WD Crew Cab Standard Box HD (d)
6.0L V83.73
4.1010,000 lbs (4 536 kg)
12,500 lbs (5 670 kg)16,000 lbs (7 257 kg)
18,500 lbs (8 391 kg)
2500 Series 2WD Regular Cab Long Box HD (d)
6.0L V83.73
4.1010,500 lbs (4 763 kg)
13,000 lbs (5 897 kg)16,000 lbs (7 257 kg)
18,500 lbs (8 391 kg)
4-60

Maintenance When Trailer Towing
The vehicle needs service more often when pulling a
trailer. See this manual’s Maintenance Schedule or Index
for more information. Things that are especially important
in trailer operation are automatic transmission uid,
engine oil, axle lubricant, belts, cooling system and brake
system. It is a good idea to inspect these before and
during the trip.
Check periodically to see that all hitch nuts and bolts
are tight.
Trailer Wiring Harness
The vehicle is equipped with one of the following
wiring harnesses for towing a trailer or hauling a
slide-in camper.
Basic Trailer Wiring
All regular, extended cab and crew cab pickups have a
seven-wire trailer towing harness.
For vehicles not equipped with heavy duty trailering,
the harness is secured to the vehicle’s frame behind the
spare tire mount. The harness requires the installation
of a trailer connector, which is available through
your dealer/retailer.
If towing a light-duty trailer with a standard four-way
round pin connector, an adapter is available from your
dealer/retailer.
4-81