2020 GMC Sierra 1500 Owners Manual - Electrical System

Electrical System

The vehicle has fuses to protect against an electrical system overload. Fuses also protect power devices in the vehicle.

Replace a bad fuse with a new one of the identical size and rating.

If there is a problem on the road and a fuse needs to be replaced, there are some spare fuses and a fuse puller in the left instrument panel fuse block. The same amperage fuse can also be borrowed. Choose some feature of the vehicle that is not needed to use and replace it as soon as possible.

An electrical overload may cause the lamps to go on and off, or in some cases to remain off. Have the headlamp wiring checked right away if the lamps go on and off or

remain off.

If the wiper motor overheats due to heavy snow or ice, the windshield wipers will stop until the motor cools and will then restart.

Although the circuit is protected from electrical overload, overload due to heavy snow or ice may cause wiper linkage damage.

Always clear ice and heavy snow from the windshield before using the windshield wipers.

If the overload is caused by an electrical problem and not snow or ice, be sure to get it fixed.

The wiring circuits in the vehicle are protected from short circuits by a combination of fuses and circuit breakers. This greatly reduces the chance of damage caused by electrical problems.

To check a fuse, look at the

silver-colored band inside the fuse. If the band is broken or melted, replace the fuse. Be sure to replace a bad fuse with a new one of the identical size and rating.

Fuses of the same amperage can be temporarily borrowed from another fuse location, if a fuse goes out. Replace the fuse as soon as possible.

If the vehicle has a diesel engine, see the Duramax diesel supplement.

The engine compartment fuse block is in the engine compartment, on the passenger side of the vehicle for 1500 and driver side of vehicle for 2500/3500.

Lift the cover to access the fuse block.

A fuse puller is available in the left instrument panel end cap.

The vehicle may not be equipped with all of the fuses, relays, and features shown.

Fuses Usage

High-beam left

Fuses Usage

High-beam right

Headlamp left

Fuses Usage

Headlamp right

6 TIM

7 –

Fog lamp

VKM

10 –

11 Police upfitter

12 –

Washer front

Washer rear

MSB driver

16 –

17 IECL 1

DC/AC inverter

IECR 2 (LD) / EBCM2 (HD)

MSB pass

IECL 2

EBCM 1

REC

Fuses Usage

76 Electric RNG BDS

Engine control module

Auxiliary battery

Cabin cooling pump

Trailer stop/turn lamp right

TIM

FTZM

Trailer brake

ENG

Engine control module

Injector B even

O2 B sensor

O2 A sensor

Injector A odd

Engine control module throttle control

Cool fan clutch

Relays Usage

5 Headlamp

18 DC/AC inverter

23 Rear window defogger

Parking lamp

Run/Crank

43 Second fuel pump

59 A/C clutch

64 Starter Motor (LD & HD DSL) / Cool Fan Clutch

(HD Gas)

70 Starter Pinion (LD)

/ Starter Motor (HD Gas)

77 Powertrain

The left instrument panel fuse block access door is on the driver side edge of the instrument panel.

The vehicle may not be equipped with all of the fuses, relays, and features shown.

Pull off the cover to access the fuse block. A fuse puller is available in the left instrument panel end cap.

Fuses Usage

F1 Rear heated seats left/right

F3 Euro trailer

F4 –

F5 Front Bolster

F6 Heated and ventilated seats left/right

F8 Rear seat entertainment/Theft deterrent

F9 Passive entry/Passive

Fuses Usage

F17 MFEG

F18 –

F20 Endgate

F22 Rear sliding window F23 –

F24 –

F25 –

F26 –

F27 –

start/Driver seat module

F10 –

F11 Sunshade

Circuit Breakers

CB1 –

Usage

The vehicle may not be equipped with all of the fuses, relays, and features shown.

F12 Passenger power seat F13 Export power take off/

Special equipment option 1

F14 –

F15 –

F16 AMP

Relays Usage

K1 Rear sliding window open

K2 Rear sliding window close

K3 MFEG major 1

K4 MFEG minor 1

Relays Usage

K5 MFEG minor 2

K6 MFEG major 2

K7 Anti-theft

K8 –

The right instrument panel fuse block access door is on the passenger side edge of the instrument panel.

Pull off the cover to access the front of the fuse block.

To access the back of the fuse block:

Push the tab at the top of fuse block down.

Pull the top of the fuse block outward.

Reverse Steps 1–2 to reinstall.

Back

The vehicle may not be equipped with all of the fuses, relays, and features shown.

Fuses Usage

F1 Right doors

F2 Left doors

F3 Universal remote system

F4 –

F5 –

F6 Front blower

F8 Lumbar switch

F10 Body control module 6/Body control module 7

F11 Seat/CLM

F12 Body control module 3/Body control module 5

F14 Mirrors/Windows module

F17 Steering wheel controls

F18 VPM/OBS DET

Fuses Usage

F19 DLIS

F20 Ventilated seats

F21 NOT R/C

F22 Heated steering wheel F23 MISC R/C

F24 Instrument panel

cluster ignition/ Overhead

F25 Heating, ventilation,

and air conditioning ignition/Heating, ventilation, and air conditioning auxiliary

F26 USB ports/Special

equipment option retained accessory power

F27 Accessory power

outlet/retained accessory power

F28 Accessory power

outlet/Battery

Fuses Usage

F30 Sensing and diagnostic module/ Parking brake

F31 Body control module 4 F32 Special equipment

option/Data link connection

F33 Body control module 8 F34 Cargo lamp

F40 CGM

F41 Infotainment 1

F42 TCP

Fuses Usage

F49 Body control module 1 F50 –

F51 Battery 1

F52 Battery 2

F53 –

F54 Sunroof

F55 Driver power seat F56 DC DC TRANS 1 F57 DC DC TRANS 2

F58 Infotainment 2

Relays Usage

K1 Run/Crank

K2 Retained accessory power/Accessory 1

K4 Retained accessory power/Accessory 2

K5 –

F43 –

F44 AVM

Circuit Breakers

Usage

F45 Body control module 2 F46 Heating, ventilation,

and air conditioning/ Battery 1

F47 Instrument panel

cluster/Battery

F48 Transmission control

module

Accessory power outlet 2

Accessory power outlet 1/Cigarette Lighter

Accessory power outlet 3

Accessory power outlet 4