2005 GMC ENVOY XL trailer

If No Steam Is Coming From
Your Engine
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.
If you get the overheat warning with no sign of steam,
try this for a minute or so:
1. In heavy traffic, let the engine idle in NEUTRAL (N)
while stopped. If it is safe to do so, pull off the road,
shift to PARK (P) or NEUTRAL (N) and let the
engine idle.
2. Turn on your heater to full hot at the highest fan
speed and open the windows as necessary.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, you can 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.
You may decide not to lift the hood but to get service
help right away.
5-27

6. Start the engine and let it run until you can feel the
upper radiator hose getting hot. Watch out for the
engine cooling fan.
7. By this time, the coolant level inside the radiator
ller neck may be lower. If the level is lower, add
more of the proper DEX-COOL
®coolant mixture
through the ller neck until the level reaches
the base of the ller neck.
8. Then replace the pressure cap. At any time during
this procedure if coolant begins to ow out of the
ller neck, reinstall the pressure cap. Be sure
the pressure cap is hand-tight and fully seated.
Engine Fan Noise
Your vehicle has a clutched engine cooling fan. When
the clutch is engaged, the fan spins faster to provide
more air to cool the engine. In most everyday driving
conditions the clutch is not engaged. This improves fuel
economy and reduces fan noise. Under heavy vehicle
loading, trailer towing, and/or high outside temperatures,
the fan speed increases when the clutch engages so
you may hear an increase in fan noise. This is normal
and should not be mistaken as the transmission slipping
or making extra shifts. It is merely the cooling system
functioning properly. The fan will slow down when
additional cooling is not required and the clutch
disengages.
You may also hear this fan noise when you start the
engine. It will go away as the fan clutch disengages.
5-33

Fuses Usage
1Electrically-Controlled Air
Suspension
2Passenger’s Side High-Beam
HeadlampFuses Usage
3Passenger’s Side Low-Beam
Headlamp
4 Back-Up Trailer Lamps L6 Engine
5-93

Fuses Usage
5Driver’s Side High-Beam
Headlamp
6Driver’s Side Low-Beam
Headlamp
7Rear Window Washer, Headlamp
Washer
8 Active Transfer Case
9 Windshield Washer
10 Powertrain Control Module B
11 Fog Lamps
12 Stoplamp
13 Cigarette Lighter
14 Ignition Coils
15 Electric Adjustable Pedals
16 Truck Body Controller, Ignition 1
17 Crank
18 Airbag
19 Trailer Electric Brake
20 Cooling Fan
21 HornFuses Usage
22 Ignition E
23 Electronic Throttle Control
24Instrument Panel Cluster, Driver
Information Center
25Automatic Shift Lock Control
System
26 Engine 1
27 Backup
28 Powertrain Control Module 1
29 Oxygen Sensor
30 Air Conditioning
31 Truck Body Controller
32 Trailer
33 Anti-Lock Brakes (ABS)
34 Ignition A
35 Blower Motor
36 Ignition B
50 Passenger’s Side Trailer Turn
51 Driver’s Side Trailer Turn
52 Hazard Flashers
5-94

Fuses Usage
1Electrically-Controlled Air
Suspension
2Passenger’s Side High-Beam
HeadlampFuses Usage
3Passenger’s Side Low-Beam
Headlamp
4 Back-Up Trailer Lamps V8 Engine
5-96

Fuses Usage
5Driver’s Side High-Beam
Headlamp
6Driver’s Side Low-Beam
Headlamp
7Rear Window Washer, Headlamp
Washer
8 Active Transfer Case
9 Windshield Washer
10 Powertrain Control Module B
11 Fog Lamps
12 Stoplamp
13 Cigarette Lighter
14 Ignition Coils
15 Canister Vent
16 Truck Body Controller, Ignition 1
17 Crank
18 Airbag
19 Trailer Electric Brake
20 Cooling Fan
21 Horn
22 Ignition E
23 Electronic Throttle ControlFuses Usage
24Instrument Panel Cluster, Driver
Information Center
25Automatic Shift Lock Control
System
26 Engine 1
27 Backup
28 Powertrain Control Module 1
29 Powertrain Control Module
30 Air Conditioning
31 Injector Bank A
32 Trailer
33 Anti-Lock Brakes (ABS)
34 Ignition A
35 Blower Motor
36 Ignition B
50 Passenger’s Side Trailer Turn
51 Driver’s Side Trailer Turn
52 Hazard Flashers
53 Transmission
54 Oxygen Sensor Bank B
55 Oxygen Sensor Bank A
56 Injector Bank B
5-97

Fuses Usage
24 Unlock
25 Blank
26 Blank
27OnStar
®Overhead
Battery/OnStar®System
28 Sunroof
29 Rainsense™ Wipers
30 Parking Lamps
31 Truck Body Controller Accessory
32 Truck Body Controller 5
33 Front Wipers
34 Vehicle Stop
35 Transmission Control Module
36Heat Ventilation Air
Conditioning B
37 Front Parking Lamps
38 Left Turn Signal
39Heat Ventilation Air
Conditioning 1
40 Truck Body Controller 4
41 Radio
42 Trailer Park
43 Right Turn Signal
44 Heat Ventilation Air Conditioning
Fuses Usage
45 Rear Fog Lamps
46 Auxiliary Power 1
47 Ignition 0
48 Four-Wheel Drive
49 Blank
50 Truck Body Controller Ignition
51 Brakes
52 Truck Body Controller Run
Envoy XL
5-100

Fuses Usage
22 Retained Accessory Power
23 Blank
24 Unlock
25 Blank
26 Blank
27OnStar
®Overhead
Battery/OnStar®System
28 Sunroof
29 Rainsense™ Wipers
30 Parking Lamps
31 Truck Body Controller Accessory
32 Truck Body Controller 5
33 Front Wipers
34 Vehicle Stop
35 Transmission Control Module
36Heat Ventilation Air
Conditioning B
37 Front Parking Lamps
38 Left Turn Signal
39Heat Ventilation Air
Conditioning 1
Fuses Usage
40 Truck Body Controller 4
41 Radio
42 Trailer Park
43 Right Turn Signal
44 Heat Ventilation Air Conditioning
45 Rear Fog Lamps
46 Auxiliary Power 1
47 Ignition 0
48 Four-Wheel Drive
49 Blank
50 Truck Body Controller Ignition
51 Brakes
52 Truck Body Controller Run
BLANK Blank
BLANK Blank
BLANK Blank
BLANK Blank
BLANK Blank
BLANK Blank
5-102