2007 GMC SIERRA CLASSIC engine coolant

If your vehicle has a low coolant level sensor, this
message will appear on the DIC if the engine
coolant level is low. Adding coolant to the coolant
recovery tank will clear the message. See
Cooling System on page 508. Pressing any of the
four DIC buttons will acknowledge the message
and clear it from the DIC display. If your
vehicle does not have the four DIC buttons,
pressing the trip odometer reset stem will
acknowledge the message and clear it from the
DIC display.
OIL LIFE RESET
This message will appear on the display for about
10 seconds after resetting the change engine
oil message. See “Engine Oil Life System” under
DIC Operation and Displays on page 266and
Engine Oil (Gasoline Engine) on page 486
for more information.
OIL PRESSURE LOW
Notice:If you drive your vehicle while the
engine oil pressure is low, severe engine
damage may occur. If a low oil pressure
warning appears on the Driver Information
Center (DIC), stop the vehicle as soon as
possible. Do not drive the vehicle until the
cause of the low oil pressure is corrected. See
Engine Oil (Gasoline Engine) on page 486
for more information.
If low oil pressure levels occur, this message will
be displayed on the DIC and a chime will
sound. Stop the vehicle as soon as safely possible
and do not operate it until the cause of the low
oil pressure has been corrected. Check the oil as
soon as possible and have your vehicle serviced
by your dealer. SeeEngine Oil (Gasoline Engine)
on page 486.
275

PASSENGER DOOR AJAR
If the passenger’s door is not fully closed, this
message will appear on the display and you will
hear a chime. Stop and turn off the vehicle, check
the door for obstructions, and close the door
again. Check to see if the message still appears
on the DIC. Pressing any of the four DIC
buttons will acknowledge the message and clear it
from the DIC display. If your vehicle does not
have the four DIC buttons, pressing the trip
odometer reset stem will acknowledge the
message and clear it from the DIC display.
RANGE SHIFT INHIBITED
(Allison Transmission®Only)
If the transmission is unable to shift into a selected
gear, this message will appear on the DIC. The
electronic shift position indicator on the instrument
panel cluster may blink when this occurs. To
make the vehicle shift to the requested gear, you
may have to shift back to PARK (P) or
NEUTRAL (N) and re-select the desired gear.
REDUCED ENGINE POWER
This message is displayed when the cooling
system temperature gets too hot and the engine
further enters the engine coolant protection mode.
SeeEngine Overheating on page 505for further
information.
This message will also display when the vehicle’s
engine power is reduced. Reduced engine
power can affect the vehicle’s ability to accelerate.
If this message is on, but there is no reduction
in performance, proceed to your destination. The
performance may be reduced the next time
the vehicle is driven. The vehicle may be driven at
a reduced speed while this message is on, but
acceleration and speed may be reduced. Anytime
this message stays on, the vehicle should be
taken to your dealer for service as soon as
possible.
276

Turn Signals When Towing a Trailer
The arrows on your instrument panel will
ash whenever you signal a turn or lane change.
Properly hooked up, the trailer lamps will also
ash, telling other drivers you’re about to
turn, change lanes or stop.
When towing a trailer, the arrows on your
instrument panel will ash for turns even if the
bulbs on the trailer are burned out. Thus, you may
think drivers behind you are seeing your signal
when they are not. It’s important to check
occasionally to be sure the trailer bulbs are still
working.
Driving On Grades
Reduce speed and shift to a lower gearbefore
you start down a long or steep downgrade. If you
don’t shift down, you might have to use your
brakes so much that they would get hot and no
longer work well.
If you have an automatic transmission, you can
tow in DRIVE (D). You may want to shift the
transmission to lower gear selection if the
transmission shifts too often (e.g., under heavy
loads and/or hilly conditions).You may also want to activate the tow/haul mode
if the transmission shifts too often. SeeTow/Haul
Mode Light on page 264.
If you have a 5-speed manual transmission and
you are towing a trailer, it’s better not to use
FIFTH (5) gear. Just drive in FOURTH (4) gear
(or, as you need to, a lower gear).
When towing at high altitude on steep uphill
grades, consider the following: Engine coolant at
or near sea level will boil at a lower temperature
than at higher altitudes. If you turn your engine off
immediately after towing at high altitude on
steep uphill grades, your vehicle may show signs
similar to engine overheating. To avoid this, let
the engine run while parked, preferably on
level ground, with the automatic transmission in
PARK (P) for a few minutes before turning
the engine off. For manual transmissions, let the
engine run while parked, preferably on level
ground, with the transmission out of gear and the
parking brake applied, for a few minutes before
turning the engine off. If you do get the overheat
warning, seeEngine Overheating on page 505.
453

Service........................................................ 468
Accessories and Modications................... 468
California Proposition 65 Warning.............. 469
Doing Your Own Service Work.................. 469
Adding Equipment to the Outside of
Your Vehicle.......................................... 470
Fuel............................................................. 470
Gasoline Octane........................................ 470
Gasoline Specications.............................. 471
California Fuel........................................... 471
Additives................................................... 472
Fuel E85 (85% Ethanol)............................ 473
Fuels in Foreign Countries........................ 474
Filling the Tank......................................... 474
Filling a Portable Fuel Container............... 477
Checking Things Under the Hood.............. 478
Hood Release........................................... 479
Engine Compartment Overview.................. 480
Engine Oil (Gasoline Engine).................... 486
Engine Oil Life System
(Gasoline Engine).................................. 489
Engine Air Cleaner/Filter
(Gasoline Engines)................................. 491Automatic Transmission Fluid
(Allison Transmission®) .......................... 494
Automatic Transmission Fluid
(Except Allison Transmission
®) ............... 497
Manual Transmission Fluid........................ 500
Hydraulic Clutch........................................ 501
Engine Coolant.......................................... 502
Coolant Surge Tank Pressure Cap............ 505
Engine Overheating................................... 505
Overheated Engine Protection
Operating Mode (V8 Engines Only)........ 508
Cooling System......................................... 508
Engine Fan Noise..................................... 514
Power Steering Fluid ................................. 515
Windshield Washer Fluid........................... 516
Brakes...................................................... 517
Battery...................................................... 520
Jump Starting............................................ 521
Rear Axle.................................................... 527
Four-Wheel Drive........................................ 528
Front Axle................................................... 529
Section 5 Service and Appearance Care
465

Checking Things Under
the Hood
{CAUTION:
An electric fan under the hood can start up
and injure you even when the engine is not
running. Keep hands, clothing, and tools
away from any underhood electric fan.
{CAUTION:
Things that burn can get on hot engine
parts and start a re. These include
liquids like fuel, oil, coolant, brake uid,
windshield washer and other uids, and
plastic or rubber. You or others could be
burned. Be careful not to drop or spill
things that will burn onto a hot engine.
478

A. Engine Air Cleaner/Filter. SeeEngine Air
Cleaner/Filter (Gasoline Engines) on page 491.
B. Coolant Surge Tank and Pressure Cap. See
Engine Coolant on page 502andCoolant
Surge Tank Pressure Cap on page 505.
C. Air Filter Restriction Indicator (If Equipped).
SeeEngine Air Cleaner/Filter (Gasoline
Engines) on page 491.
D. Engine Oil Dipstick. See “Checking Engine Oil”
underEngine Oil (Gasoline Engine) on
page 486.
E. Automatic Transmission Fluid Dipstick
(If Equipped). See “Checking the Fluid Level”
underAutomatic Transmission Fluid (Allison
Transmission
®) on page 494orAutomatic
Transmission Fluid (Except Allison
Transmission
®) on page 497.
F. Engine Cooling Fan. SeeCooling System on
page 508.G. Engine Oil Fill Cap. See “When to Add Engine
Oil” underEngine Oil (Gasoline Engine) on
page 486.
H. Power Steering Fluid Reservoir. SeePower
Steering Fluid on page 515.
I. Remote Negative (−) Terminal (GND). See
Jump Starting on page 521.
J. Remote Positive (+) Terminal. SeeJump
Starting on page 521.
K. Brake Fluid Reservoir. See “Brake Fluid” under
Brakes on page 517.
L. Clutch Fluid Reservoir (If Equipped). See
Hydraulic Clutch on page 501.
M. Underhood Fuse Block. SeeUnderhood Fuse
Block on page 603.
N. Battery. SeeBattery on page 520.
O. Windshield Washer Fluid Reservoir. See
“Adding Washer Fluid” underWindshield
Washer Fluid on page 516.
481

A. Engine Air Cleaner/Filter. SeeEngine Air
Cleaner/Filter (Gasoline Engines) on page 491.
B. Coolant Surge Tank and Pressure Cap. See
Engine Coolant on page 502andCoolant
Surge Tank Pressure Cap on page 505.
C. Air Filter Restriction Indicator (If Equipped).
SeeEngine Air Cleaner/Filter (Gasoline
Engines) on page 491.
D. Engine Oil Dipstick. See “Checking Engine Oil”
underEngine Oil (Gasoline Engine) on
page 486.
E. Automatic Transmission Fluid Dipstick
(If Equipped). See “Checking the Fluid Level”
underAutomatic Transmission Fluid (Allison
Transmission
®) on page 494orAutomatic
Transmission Fluid (Except Allison
Transmission
®) on page 497.
F. Engine Oil Fill Cap. See “When to Add Engine
Oil” underEngine Oil (Gasoline Engine) on
page 486.G. Engine Cooling Fan. SeeCooling System on
page 508.
H. Remote Negative (−) Terminal (GND). See
Jump Starting on page 521.
I. Power Steering Fluid Reservoir. SeePower
Steering Fluid on page 515.
J. Remote Positive (+) Terminal. SeeJump
Starting on page 521.
K. Brake Fluid Reservoir. See “Brake Fluid” under
Brakes on page 517.
L. Clutch Fluid Reservoir (If Equipped). See
Hydraulic Clutch on page 501.
M. Underhood Fuse Block. SeeUnderhood Fuse
Block on page 603.
N. Battery. SeeBattery on page 520.
O. Windshield Washer Fluid Reservoir. See
“Adding Washer Fluid” underWindshield
Washer Fluid on page 516.
483

A. Engine Air Cleaner/Filter. SeeEngine Air
Cleaner/Filter (Gasoline Engines) on page 491.
B. Coolant Surge Tank and Pressure Cap. See
Engine Coolant on page 502andCoolant
Surge Tank Pressure Cap on page 505.
C. Air Filter Restriction Indicator (If Equipped).
SeeEngine Air Cleaner/Filter (Gasoline
Engines) on page 491.
D. Engine Oil Dipstick. See “Checking Engine Oil”
underEngine Oil (Gasoline Engine) on
page 486.
E. Automatic Transmission Fluid Dipstick
(If Equipped). See “Checking the Fluid Level”
underAutomatic Transmission Fluid (Allison
Transmission
®) on page 494orAutomatic
Transmission Fluid (Except Allison
Transmission
®) on page 497.
F. Engine Oil Fill Cap. See “When to Add Engine
Oil” underEngine Oil (Gasoline Engine) on
page 486.G. Engine Cooling Fan. SeeCooling System on
page 508.
H. Remote Negative (−) Terminal (GND). See
Jump Starting on page 521.
I. Remote Positive (+) Terminal. SeeJump
Starting on page 521.
J. Power Steering Fluid Reservoir. SeePower
Steering Fluid on page 515.
K. Brake Fluid Reservoir. See “Brake Fluid” under
Brakes on page 517.
L. Clutch Fluid Reservoir (If Equipped). See
Hydraulic Clutch on page 501.
M. Underhood Fuse Block. SeeUnderhood Fuse
Block on page 603.
N. Battery. SeeBattery on page 520.
O. Windshield Washer Fluid Reservoir. See
“Adding Washer Fluid” underWindshield
Washer Fluid on page 516.
485