2007 HUMMER H2 trailer

Connect the adapter with the tab pointing up.
The ip cap on the vehicle’s seven-wire harness
will lock onto the tab (see arrow in the previous
graphic) and help hold the adapter in place.
Plug the four-way round pin connector onto the
adapter.
Trailer Recommendations
You must subtract your hitch loads from the Cargo
Weight Rating (CWR). CWR is the maximum
weight of the load your vehicle can carry. It doesn’t
include the weight of the people inside, but you
can gure about 150 lbs. (68 kg) for each
seat. The total cargo load must not be more than
your vehicles CWR.
Weigh your vehicle with your trailer attached, so
that you won’t go over the GVWR or GAWR. If you
are using a weight-distributing hitch, weigh the
vehicle without the spring bars in place.
You’ll get the best performance if you spread out
the weight of your load the right way, and if
you choose the correct hitch and trailer brakes.
For more information seeTowing a Trailer
on page 374.
388

Automatic Transmission Fluid
When to Check and Change Automatic
Transmission Fluid
A good time to check your automatic transmission
uid level is when the engine oil is changed.
Change the uid and lter at the intervals listed in
Additional Required Services on page 520, and
be sure to use the transmission uid listed in
Recommended Fluids and Lubricants on page 528.
How to Check Automatic
Transmission Fluid
Because this operation can be a little difficult, you
may choose to have this done at the dealership
service department.
If you do it yourself, be sure to follow all the
instructions here, or you could get a false reading
on the dipstick.Notice:Too much or too little uid can
damage your transmission. Too much can
mean that some of the uid could come out
and fall on hot engine parts or exhaust system
parts, starting a re. Too little uid could
cause the transmission to overheat. Be sure to
get an accurate reading if you check your
transmission uid.
Wait at least 30 minutes before checking the
transmission uid level if you have been driving:
When outside temperatures are above
90°F (32°C).
At high speed for quite a while.
In heavy traffic — especially in hot weather.
While pulling a trailer.
To get the right reading, the uid should be at
normal operating temperature, which is 180°F to
200°F (82°C to 93°C).
Get the vehicle warmed up by driving about
15 miles (24 km) when outside temperatures are
above 50°F (10°C). If it is colder than 50°F (10°C),
drive the vehicle in THIRD (3) until the engine
temperature gage moves and then remains steady
for 10 minutes.
412

Notice:If your engine catches re because
you keep driving with no coolant, your vehicle
can be badly damaged. The costly repairs
would not be covered by your warranty.
SeeOverheated Engine Protection Operating
Mode on page 420for information on driving to
a safe place in an emergency.
If No Steam Is Coming From Your
Engine
The ENGINE COOLANT HOT message, along
with a low coolant condition, can indicate a serious
problem.
If you get an engine overheat warning, but see or
hear no steam, the problem may not be too
serious. Sometimes the engine can get a little
too hot when you:
Climb a long hill on a hot day.
Stop after high-speed driving.
Idle for long periods in traffic.
Tow a trailer. SeeTowing a Trailer on
page 374.If you get the ENGINE COOLANT HOT message
with no sign of steam, try this for a minute or so:
1. Turn on your heater to full hot at the highest fan
speed and open the windows as necessary.
2. If you are in a traffic jam, shift to
NEUTRAL (N); otherwise, shift to the highest
gear while driving — DRIVE (D).
If you no longer have the overheat warning,
you can drive. Just to be safe, drive slower for
about 10 minutes. If the warning does not
come back on, you can drive normally.
If the warning continues and you have not
stopped, pull over, stop, and park your vehicle
right away.
If there is still no sign of steam, push down the
accelerator until the engine speed is about
twice as fast as normal idle speed for at least
three minutes while you are parked. If you
still have the warning, turn off the engine and get
everyone out of the vehicle until it cools down.
Also, see “Overheated Engine Protection
Operating Mode” later in this section.
You may decide not to lift the hood but to get
service help right away.
419

Overheated Engine Protection
Operating Mode
If an overheated engine condition exists and the
REDUCED ENGINE POWER message is
displayed, an overheat protection mode which
alternates ring groups of cylinders helps prevent
engine damage. In this mode, you will notice a
loss in power and engine performance. This
operating mode allows your vehicle to be driven to
a safe place in an emergency. Driving extended
miles (km) and/or towing a trailer in the overheat
protection mode should be avoided.
Notice:After driving in the overheated engine
protection operating mode, to avoid engine
damage, allow the engine to cool before
attempting any repair. The engine oil will be
severely degraded. Repair the cause of coolant
loss, change the oil and reset the oil life
system. SeeEngine Oil on page 404.
Cooling System
When you decide it is safe to lift the hood, here is
what you will see:
A. Coolant Surge Tank
B. Coolant Surge Tank Pressure Cap
C. Engine Cooling Fan
If the coolant inside the coolant surge tank is
boiling, do not do anything else until it cools down.
The vehicle should be parked on a level surface.
420

Fuses Usage
RR Wiper Rear Window Wiper Switch
SEO ACCYSpecial Equipment Option
Accessory
WS WPR Windshield Wipers
TBC ACCYTruck Body Controller
Accessory
IGN 3 Rear Heated Seats Module
Fuses Usage
4WDFour-Wheel Drive Switch, Air
Suspension Switch/Module
HTR A/C Not Used
LOCKPower Door Lock Relay
(Lock Function)
HVAC 1Inside Rearview Mirror,
Climate Control System
L DOORDriver’s Door Harness
Connection
CRUISE Cruise Control
UNLOCKPower Door Lock Relay
(Unlock Function)
RR FOG LP Not Used
BRAKE Brake Switch
DRIVER UNLOCKPower Door Lock Relay
(Driver’s Door Unlock
Function)
IGN 0Brake Transmission Shift
Interlock, Powertrain Control
Module, Transmission
TBC IGN 0 Truck Body Controller
VEH CHMSLVehicle and Trailer High
Mounted Stoplamp
LT TRLR ST/TRN Left Turn Signal/Stop Trailer
505

Fuses Usage
LT TRNLeft Turn Signals and
Sidemarkers
VEH STOPVehicle Stoplamps, Brake
Module, Electronic Throttle
Control Module
RT TRLR ST/TRN Right Turn Signal/Stop Trailer
RT TRNRight Turn Signals and
Sidemarkers
BODY Harness Connector
DDM Driver Door Module
LOCKSRear Doors and Liftgate
Power Lock Relay Feed
ECC Liftgate
TBC 2C Truck Body Controller
FLASH Flasher Module
CB LT DOORSLeft Rear Power Window
Circuit Breaker and Driver
Door Module
TBC 2B Truck Body Controller
TBC 2A Truck Body Controller
Circuit Breaker Usage
AUX PWR 2 Midgate Controller (SUT Only)
Center Instrument Panel Fuse Block
The center instrument panel utility block is
located underneath the instrument panel, to the
left of the steering column.
Device Usage
SEO Special Equipment Option
TRAILERTrailer Brake Wiring,
Off-Road Lamps Harness
Connector
UPFIT Uptter (Not Used)
SL RIDE Ride Control (Not Used)
HDLR 2Headliner Wiring
Connector 2
506

*1— Gasoline Engine and Fuel Injection Rail #2.
*2— Gasoline Engine and Fuel Injection Rail
#1.
*3— Gasoline Engine; Oxygen Sensors.
*4— Gasoline Engine; Oxygen Sensors.
*5— Ignition 1
*6— Powertrain Control Module, Fuel Pump.
*7— Supplemental Brake Assist.
*8— Sunroof.
Fuses Usage
GLOW PLUG Not Used
CUST FEED Gasoline Accessory Power
HYBRID Not Used
WSW/HTRHeated Windshield Washer
(Special Edition Only)
STUD #1Accessory Power/Trailer
Wiring
MBEC 1Mid Bussed Electrical Center
Power Feed, Front Seats,
Right Doors
Fuses Usage
BLWR Front Climate Control Fan
LBEC 2Left Bussed Electrical Center,
Door Modules, Door Locks,
Auxiliary Power Outlet—Rear
Cargo Area and Instrument
Panel
STUD #2*Accessory Power/Trailer
Wiring Brake Feed
ABS Anti-lock Brakes
VSES/ECASElectronically Controlled Air
Suspension
IGN A Ignition Switch
IGN B Ignition Switch
LBEC 1Left Bussed Electrical Center,
Left Doors, Truck Body
Controller, Flasher Module
TRL PARK Parking Lamps Trailer Wiring
RR PARKPassenger’s Side Rear
Parking and Sidemarker
Lamps
LR PARKDriver’s Side Rear Parking
and Sidemarker Lamps
509

Fuses Usage
PARK LP Parking Lamps Relay
STRTR Starter Relay
INTPARK Roof Marker Lamps
STOP LP Stoplamps
TBC BATTTruck Body Controller
Battery Feed
SEO B2 Off-Road Lamps
4WS Not Used
AUX PWRInstrument Panel Outlets,
Rear Cargo Area Power
Outlets, Console
PCM 1 Powertrain Control Module
ETC/ECMElectronic Throttle Control,
Electronic Brake Controller
IGN EInstrument Panel Cluster,
Air Conditioning Relay, Turn
Signal/Hazard Switch, Starter
Relay, Electronic Brake
Controller TC2 Mode Switch
RTDElectronic Brake Controller
Battery FeedFuses Usage
TRL B/U Backup Lamps Trailer Wiring
F/PMP Fuel Pump (Relay)
B/U LPBack-up Lamps, Automatic
Transmission Shift Lock
Control System
RR DEFOG Rear Window Defogger
HDLP-HI Headlamp High Beam Relay
PRIME Not Used
AIRBAGSupplemental Inatable
Restraint System
FRT PARKFront Parking Lamps,
Sidemarker Lamps
DRLDaytime Running Lamps
(Relay)
SEO IGN Rear Defog Relay
TBC IGN1 Truck Body Controller Ignition
HI HDLP-LTDriver’s Side High Beam
Headlamp
LH HID Not Used
DRL Daytime Running Lamps
510