GMC Envoy XL 2003-2006 fuse box and relay Diagrams

Find the fuse box and relay locations for the GMC Envoy XL 2003-2006, with diagrams for easy reference. Ensure reliable performance of key electrical systems.

The GMC Envoy XL (2003-2006) is an extended-body version of the popular GMC Envoy, designed to offer increased interior space and seating for up to seven passengers. This extended body style makes it a practical choice for families or those needing extra cargo space. The Envoy XL is equipped with a range of electrical features that enhance convenience and safety, such as power windows, headlights, and climate control.

The fuse box and relays are crucial in maintaining these electrical systems. The primary fuse box is located under the hood on the driver’s side, while another may be found inside the cabin near the driver’s door. Relays, which control larger electrical loads like the starter and fuel pump, are housed in the same area. Regular inspection of the fuse box and relays is essential for reliable operation of the vehicle’s electronic functions.

MUST READ: DYI – How to Check Car Fuses?

(2003-2006) GMC Envoy XL fuse box and relay with Diagram

WARNING

• Never replace a fuse with one that has a higher amperage rating.
• A fuse with a too-high amperage could damage the electrical part and cause a fire.
• On no account should fuses be repaired (e.g. patched up with tin foil or wire) as this may cause serious damage elsewhere in the electrical circuit or cause a fire.
• If a fuse blows repeatedly, do not keep replacing it. Instead, have the cause for the repeated short circuit or overload tracked and fixed.
• Terminal and harness assignments for individual connectors will vary depending on vehicle equipment level, model, and market.

GMC Envoy XL 2003-2006 fuse assignment

GMC Envoy XL Year of production: 2003, 2004, 2005, 2006

Location of Fuse Boxes

Engine Compartment Fuse Block:

The fuse block is located under the hood in the engine compartment on the driver’s side of the vehicle.

To Access:

1. Remove the primary cover by pressing the two locking tabs.
2. Remove the secondary cover by snapping off while lifting.
3. To reinstall the fuse panel cover, reverse the sequence.

Rear Underseat Fuse Block:

The rear underseat fuse block is located under the rear seat on the driver’s side of the vehicle.

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Fuse Box Diagrams

2003

Engine Compartment Fuse Block

List of fuses in the Engine Compartment Fuse Block (2003)

№	Usage
1	Electrically-Controlled Air Suspension
2	Passenger’s Side High-Beam Headlamp
3	Passenger’s Side Low-Beam Headlamp
4	Back-Up-Trailer Lamps
5	Driver’s Side High-Beam Headlamp
6	Driver’s Side Low-Beam Headlamp
7	Wash
8	Automatic Transfer Case
9	Windshield Wipers
10	Powertrain Control Module B
11	Fog Lamps
12	Stop Lamp
13	Cigarette Lighter
14	Ignition Coils
15	Cannister Vent
16	TBD-Ignition 1
17	Crank
18	Air Bag
19	Electric Brake
20	Cooling Fan
21	Horn
22	Ignition E
23	Electronic Throttle Control
24	Instrument Panel Cluster, Driver Information Center
25	Automatic Shift Lock Control System
26	Engine 1
27	Back-Up
28	Powertrain Control Module 1
30	Air Conditioning
31	Truck Body Controller 1
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	Oxygen Sensor Bank A
54	Oxygen Sensor Bank B
55	Injector Bank A
56	Injector Bank B
Relays
37	Headlamp Washer
38	Rear Window Washer
39	Fog Lamps
40	Horn
41	Fuel Pump
42	Windshield Wipers/Washer
43	High-Beam Headlamp
44	Air Conditioning
45	Cooling Fan
46	Headlamp Driver Module
47	Starter
58	Ignition 1
Miscellaneous
48	Instrument Panel Battery

Rear Underseat Fuse Block

List of fuses in the Rear Underseat Fuse Block (2003)

№	Usage
01	Right Door Control Module
02	Left Door Control Module
03	Liftgate Module 2
04	Truck Body Controller 3
05	Rear Fog Lamps
06	Liftgate Module / Driver Seat Module
07	Truck Body Controller 2
08	Power Seats
09	Rear Wiper
10	Driver Door Module
11	Amplifier
12	Passenger Door Module
13	Rear Climate Controls
14	Left Rear Parking Lamps
15	Auxiliary Power 2
16	Vehicle Center High-Mounted Stop Lamp
17	Right Rear Parking Lamps
18	Locks
19	Blank
20	Vent Window
21	Lock
22	Retained Accessory Power
23	Blank
24	Unlock
25	Blank
26	Blank
27	OH Battery / OnStar System
28	Sunroof
29	Rainsense Wipers
30	Parking Lamps
31	Truck Body Controller 4 Cruise Control
32	Truck Body Controller 5
33	Front Wipers
34	Vehicle Stop
35	Blank
36	Heat Ventilation Air Conditioning B
37	Front Parking Lamps
38	Left Turn Signal
39	Heat Ventilation Air Conditioning 1
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

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2004

Engine Compartment Fuse Block

List of fuses in the Engine Compartment Fuse Block (2004)

№	Usage
1	Electrically-Controlled Air Suspension
2	Passenger’s Side High-Beam Headlamp
3	Passenger’s Side Low-Beam Headlamp
4	Back-Up-Trailer Lamps
5	Driver’s Side High-Beam Headlamp
6	Driver’s Side Low-Beam Headlamp
7	Rear Window Washer, Headlamp Washer
8	Active Transfer Case
9	Windshield Washer
10	Powertrain Control Module B
11	Fog Lamps
12	Stop Lamp
13	Cigarette Lighter
14	Ignition Coils
15	Canister Vent
16	TBC-Ignition 1
17	Crank
18	Air Bag
19	Trailer Electric Brake
20	Cooling Fan
21	Horn
22	Ignition E
23	Electronic Throttle Control
24	Instrument Panel Cluster, Driver Information Center
25	Automatic Shift Lock Control System
26	Backup
27	Engine 1
28	Powertrain Control Module 1
30	Air Conditioning
31	Truck Body Controller 1
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	Oxygen Sensor Bank B
54	Oxygen Sensor Bank A
55	Injector Bank A
56	Injector Bank B
57	Electric Adjustable Pedal
Relays
37	Headlamp Washer
38	Rear Window Washer
39	Fog Lamps
40	Horn
41	Fuel Pump
42	Windshield Washer
43	High-Beam Headlamp
44	Air Conditioning
45	Cooling Fan
46	Headlamp Driver Module
47	Starter
49	Electric Adjustable Pedal
58	Ignition 1
Miscellaneous
48	Instrument Panel Battery

Rear Underseat Fuse Block

List of fuses in the Rear Underseat Fuse Block (2004)

№	Usage
01	Right Door Control Module
02	Left Door Control Module
03	Liftgate Module 2
04	Truck Body Controller 3
05	Rear Fog Lamps
06	Blank
07	Truck Body Controller 2
08	Power Seats
09	Rear Wiper
10	Driver Door Module
11	Amplifier
12	Passenger Door Module
13	Rear Climate Controls
14	Left Rear Parking Lamps
15	Blank
16	Vehicle Center High-Mounted Stop Lamp
17	Right Rear Parking Lamps
18	Locks
19	Liftgate Module / Driver Seat Module
20	Vent Window
21	Lock
22	Retained Accessory Power
23	Blank
24	Unlock
25	Blank
26	Blank
27	OH 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	Blank
36	Heat Ventilation Air Conditioning B
37	Front Parking Lamps
38	Left Turn Signal
39	Heat Ventilation Air Conditioning 1
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

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2005

Engine Compartment Fuse Block

List of fuses in the Engine Compartment Fuse Block (2005)

№	Usage
1	Electrically-Controlled Air Suspension
2	Passenger’s Side High-Beam Headlamp
3	Passenger’s Side Low-Beam Headlamp
4	Back-Up Trailer Lamps
5	Driver’s Side High-Beam Headlamp
6	Driver’s Side Low-Beam Headlamp
7	Rear 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 Control
24	Instrument Panel Cluster, Driver Information Center
25	Automatic 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
57	Headlamp Driver Module
58	Truck Body Controller 1
59	Electric Adjustable Pedal
Relays
37	Headlamp Washer
38	Rear Window Washer
39	Fog Lamps
40	Horn
41	Fuel Pump
42	Windshield Washer
43	High-Beam Headlamp
44	Air Conditioning
45	Cooling Fan
46	Headlamp Driver Module
47	Starter
49	Electric Adjustable Pedal
60	Powertrain
Miscellaneous
48	Instrument Panel Battery

Rear Underseat Fuse Block

List of fuses in the Rear Underseat Fuse Block (2005)

№	Usage
01	Right Door Control Module
02	Left Door Control Module
03	Liftgate Module 2
04	Truck Body Controllers
05	Rear Fog Lamps
06	Blank
07	Truck Body Controller 2
08	Power Seats
09	Rear Wiper
10	Driver Door Module
11	Amplifier
12	Passenger Door Module
13	Rear Climate Controls
14	Left Rear Parking Lamps
15	Blank
16	Vehicle Center High-Mounted Stop Lamp
17	Right Rear Parking Lamps
18	Locks
19	Liftgate Module / Driver Seat Module
20	Vent Window
21	Lock
22	Retained Accessory Power
23	Blank
24	Unlock
25	Blank
26	Blank
27	OnStar 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
36	Heat Ventilation Air Conditioning B
37	Front Parking Lamps
38	Left Turn Signal
39	Heat Ventilation Air Conditioning 1
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

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2006

Engine Compartment Fuse Block

List of fuses in the Engine Compartment Fuse Block (2006)

№	Usage
1	Electrically-Controlled Air Suspension
2	Passenger’s Side High-Beam Headlamp
3	Passenger’s Side Low-Beam Headlamp
4	Back-Up Trailer Lamps
5	Driver’s Side High-Beam Headlamp
6	Driver’s Side Low-Beam Headlamp
7	Rear 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 Control
24	Instrument Panel Cluster, Driver Information Center
25	Automatic 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
57	Headlamp Driver Module
58	Truck Body Controller 1
59	Electric Adjustable Pedal
Relays
37	Headlamp Washer
38	Rear Window Washer
39	Fog Lamps
40	Horn
41	Fuel Pump
42	Windshield Washer
43	High-Beam Headlamp
44	Air Conditioning
45	Cooling Fan
46	Headlamp Driver Module
47	Starter
49	Electric Adjustable Pedal
60	Powertrain
61	Vehicle Stability Enhancement System (StabiliTrak)
Miscellaneous
48	Instrument Panel Battery

Rear Underseat Fuse Block

List of fuses in the Rear Underseat Fuse Block (2006)

№	Usage
01	Right Door Control Module
02	Left Door Control Module
03	Liftgate Module 2
04	Truck Body Controllers
05	Rear Fog Lamps
06	Blank
07	Truck Body Controller 2
08	Power Seats
09	Rear Wiper
10	Driver Door Module
11	Amplifier
12	Passenger Door Module
13	Rear Climate Controls
14	Left Rear Parking Lamps
15	Blank
16	Vehicle Center High-Mounted Stop Lamp
17	Right Rear Parking Lamps
18	Locks
19	Liftgate Module / Driver Seat Module
20	Vent Window
21	Lock
22	Retained Accessory Power
23	Blank
24	Unlock
25	Blank
26	Blank
27	OnStar 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
36	Heat Ventilation Air Conditioning B
37	Front Parking Lamps
38	Left Turn Signal
39	Heat Ventilation Air Conditioning 1
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

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Conclusion

The GMC Envoy XL 2003-2006 offers both comfort and functionality, supported by a robust electrical system. Maintaining the fuse box and relays is key to ensuring reliable performance of its features.