engine overheat GMC YUKON HYBRID 2010 Owners Manual

Leaving the Vehicle With the Engine
Running
{WARNING:
It can be dangerous to leave the vehicle with the
engine running. The vehicle could move suddenly
if the shift lever is not fully in P (Park) with the
parking brake firmly set.
If you have four-wheel drive and the transfer case
is in N (Neutral), the vehicle will be free to roll,
even if the shift lever is in P (Park). So be sure
the transfer case is in a drive gear—not in
N (Neutral).
And, if you leave the vehicle with the engine
running, it could overheat and even catch fire.
You or others could be injured. Do not leave the
vehicle with the engine running unless you
have to. If you have to leave the vehicle with the engine running,
be sure your vehicle is in P (Park) and the parking
brake is firmly set before you leave it. After you move
the shift lever into P (Park), hold the regular brake pedal
down. Then, see if you can move the shift lever away
from P (Park) without first pulling it toward you. If you
can, it means that the shift lever was not fully locked
into P (Park).
Torque Lock
If parking on a hill and the transmission not shifted into
P (Park) properly, the weight of the vehicle may put too
much force on the parking pawl in the transmission. You
may find it difficult to pull the shift lever out of P (Park).
This is called torque lock. To prevent torque lock, set
the parking brake and then shift into P (Park) properly
before you leave the driver seat. To find out how, see
Shifting Into Park on page 3‑15.
When you are ready to drive, move the shift lever out
of P (Park) before you release the parking brake.
If torque lock does occur, you may need to have
another vehicle push yours a little uphill to take some of
the pressure from the parking pawl in the transmission,
then you will be able to pull the shift lever out of
P (Park).
3-16

Engine Coolant Heater
The engine coolant heater can provide easier starting
and better fuel economy during engine warm-up in cold
weather conditions at or below−18°C (0°F). Vehicles
with an engine heater should be plugged in at least
four hours before starting. An internal thermostat in
the plug-end of the cord may exist which will prevent
engine coolant heater operation at temperatures
above −18°C (0°F).
To Use the Engine Coolant Heater
1. Turn off the engine.
2. Open the hood and unwrap the electrical cord.
The cord is secured to a wiring harness between
the engine and the Hybrid Auxiliary Underhood
Fuse Block with a clip. Carefully remove the wire
tie which secures the electrical cord. Do not cut the
electrical cord.
3. Plug the cord into a normal, grounded 110-volt AC outlet.
{WARNING:
Plugging the cord into an ungrounded outlet could
cause an electrical shock. Also, the wrong kind of
extension cord could overheat and cause a fire.
You could be seriously injured. Plug the cord into
a properly grounded three-prong 110-volt AC
outlet. If the cord will not reach, use a heavy-duty
three-prong extension cord rated for at least
15 amps.
4. Before starting the engine, be sure to unplug and store the cord as it was before to keep it away from
moving engine parts. If you do not, it could be
damaged.
The length of time the heater should remain plugged in
depends on several factors. Ask a dealer/retailer in the
area where you will be parking the vehicle for the best
advice on this.
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A. See“Engine Air Cleaner/Filter” in the owner
manual.
B. Drive Motor/Generator Control Module (DMCM). See Drive Motor/Generator Control Module
(DMCM) Cooling System on page 6‑9.
C. Engine Oil Dipstick. See “Engine Oil”in the owner
manual.
D. Automatic Transmission Fluid Dipstick. See Automatic Transmission Fluid on page 6‑5.
E. Brake Fluid Reservoir. See Brakes on page 6‑13.
F. See “Underhood Fuse Block” in the owner manual.
G. See “Windshield Washer Fluid” in the owner
manual.
H. Hybrid Auxiliary Fuse Block. See Underhood Fuse
Block on page 6‑26.
I. DMCM Coolant Surge Tank Pressure Cap. See Drive Motor/Generator Control Module (DMCM)
Coolant Surge Tank Pressure Cap on page 6‑8.
J. See “Coolant Surge Tank Pressure Cap” in the
owner manual.
K. Engine Oil Fill Cap. See “Engine Oil”in the owner
manual.Automatic Transmission Fluid
When to Check and Change Automatic
Transmission Fluid
It is usually not necessary to check the transmission
fluid level. The only reason for fluid loss is a
transmission leak or overheating the transmission.
If you suspect a small leak, then use the following
checking procedures to check the fluid level. However,
if there is a large leak, then it may be necessary to have
the vehicle towed to a dealer/retailer service department
and have it repaired before driving the vehicle further.
Notice: Use of the incorrect automatic transmission
fluid may damage the vehicle, and the damages may
not be covered by the vehicle's warranty. Always
use the automatic transmission fluid listed in
Recommended Fluids and Lubricants on page 7‑2.
Change the fluid and filter at the intervals listed in the
Maintenance Schedule. See Scheduled Maintenance in
the owner manual. Be sure to use the transmission fluid
listed in Recommended Fluids and Lubricants
on
page 7‑2.
6-5

How to Check Automatic Transmission
Fluid
Notice:Too much or too little fluid can damage your
transmission. Too much can mean that some of the
fluid could come out and fall on hot engine parts or
exhaust system parts, starting a fire. Too little fluid
could cause the transmission to overheat. Be sure
to get an accurate reading if you check your
transmission fluid.
Before checking the fluid level, prepare the vehicle as
follows:
1. Start the engine and park the vehicle on a level surface. Keep the engine running.
2. Apply the parking brake and place the shift lever in P (Park).
3. With your foot on the brake pedal, move the shift lever through each gear range, pausing for about
three seconds in each range. Then, move the shift
lever back to P (Park).
4. Allow the engine to idle (500 –800 RPM) for at
least one minute. Slowly release the brake pedal.
5. Keep the engine running and press the Trip/Fuel button or trip odometer reset stem until TRANS
TEMP (Transmission Temperature) displays on the
Driver Information Center (DIC). 6. Using the TRANS TEMP reading, determine and
perform the appropriate check procedure. If the
TRANS TEMP reading is not within the required
temperature ranges, allow the vehicle to cool,
or operate the vehicle until the appropriate
transmission fluid temperature is reached.
Cold Check Procedure
Use this procedure only as a reference to determine if
the transmission has enough fluid to be operated safely
until a hot check procedure can be made. The hot
check procedure is the most accurate method to check
the fluid level. Perform the hot check procedure at the
first opportunity. Use this cold check procedure to check
fluid level when the transmission temperature is
between 24°C and 34°C (75°F and 93°F).
1. Locate the
transmission dipstick at
the rear of the engine
compartment, on the
passenger side of the
vehicle.
See Engine Compartment Overview
on page 6‑4for more information.
2. Pull out the dipstick and wipe it with a clean rag or paper towel.
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