7.4

pretty bad
Crashes / Fires:
0 / 0
Injuries / Deaths:
0 / 0
Average Mileage:
7,073 miles

About These NHTSA Complaints:

This data is from the NHTSA — the US gov't agency tasked with vehicle safety. Complaints are spread across multiple & redundant categories, & are not organized by problem.

So how do you find out what problems are occurring? For this NHTSA complaint data, the only way is to read through the comments below. Any duplicates or errors? It's not us.

2020 GMC Sierra 1500 electrical problems

electrical problem

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2020 GMC Sierra 1500 Owner Comments (Page 1 of 2)

problem #36

Dec 302022

Sierra 1500

  • 44,000 miles

A D V E R T I S E M E N T S

The contact owns a 2020 GMC Sierra 1500. The contact stated while driving at various speeds, the vehicle was stuck in gear. While driving there was an abnormal burning odor coming from the vehicle. The vehicle failed to start on several occasions. There were sparks from the passenger's side front seat. Several unknown warning lights were illuminated. The vehicle was taken to the local dealer, where it was diagnosed with electrical, transmission module, wiring harness, air alternator cooler, and exhaust system failures. The vehicle was repaired; however, the failure recurred. Additionally, while driving at undisclosed speeds, there was a failure with the vault meter. The OnStar system provided an error with the antilock braking system. The manufacturer was contacted, but no assistance was provided. The failure mileage was approximately 44,000.

- Brighton, MI, USA

problem #35

Apr 282024

Sierra 1500 6-cyl Diesel

  • miles
My wiring harness which affects all systems. I was on the Interstate when out of nowhere any and all warning lights came on. The power was cut and rapidly slowed down. I also pulled into traffic and the truck just lost power. The problem was confirmed by dealership. The vehicle was inspected by dealership and wiring harness was the issue. The issues appeared out of nowhere. All the warnings lights came on at once. There has been numerous issues with this part and it-??s even recognized by just.

- Folsom, LA, USA

problem #34

Mar 092022

Sierra 1500

  • miles
The rear sliding window leaks water inside the cab every time it rains. With water getting into the cab the issue of mold has begun and that could be a serious factor to any children or adults that ride inside the cab of the truck. There is also rust issues that are notable under the rear seats of the vehicle. Water inside the cab can also interact negatively with any electrical components of the vehicle. I tried to get ahold of the dealer and they always say they don't have time to get my truck in. I have read that this has happened to other vehicles that are the same year and model and they just fix it with caulk which does not seem appropriate for a almost new vehicle. The vehicle has not been inspected. There were no warning lamps prior to this issue. A possible symptom was that my back up camera stopped working for a day right after a rain.

- Corning, CA, USA

problem #33

Mar 042024

Sierra 1500

  • miles

A D V E R T I S E M E N T S

Back window frame crack led to water intrusion which flooded electric module controlling speedometer and adaptive settings. Extremely unsafe driving with faulty electrical components unknown to me. Insurance and Dealership told me this is a common GMC occurrence. Cost is near $10,000 to make truck drivable.

- Arbuckle, CA, USA

problem #32

Jul 312023

Sierra 1500

  • miles
Electronic power steering stops working randomly which makes it nearly impossible to safely drive the vehicle. The strength needed to turn the vehicle is so great that the steering wheel elevation lock fails and the wheel slams to the lowest limit of travel. Problem started around 50,000 miles and was only a warning that went away as soon as I got in the truck again. However reappeared today and the steering went out this time. The GM dealer in Mexia Texas didn't know what was wrong, I am taking it to a dealer in Corsicana tomorrow. This is a known problem that GM has had in the past however my vehicle has no active recall to make my truck safe free of charge. This puts myself and other drivers at risk because there would be no way to rapidly maneuver the vehicle to avoid a colision.

- Mexia, TX, USA

problem #31

Feb 272023

Sierra 1500

  • miles
We are unsure what happened that caused the issue. One day the dashboard just started giving us error messages, 3 of them to be specific. One says check turn signals, another says check trailer brake light and another something else about brakes or turn signals. (We have to dismiss them all before anything on the dash is viewable). This issue is causing the blinkers to blink fast as though the blinker lights need replaced and it happens when turning right or left. The alerts continue to give us error messages every few minutes, even after we have dismissed them all. We had the truck at a shop trying to figure out the issue and his guys spent hours and replaced things he thought were causing the issue but nothing fixed it. He referred us to take it to the dealership service shop for troubleshooting so we took it to the GMC dealer where we bought the truck. GMC has already spent hours, maybe 5-7 hours at $150 per hour, trying to figure out what's wrong and have been unable to find anything wrong. The truck is still at the GMC dealership shop but I can get pictures of the errors when we get it back.

- Blaine, MN, USA

problem #30

Feb 102023

Sierra 1500

  • miles

A D V E R T I S E M E N T S

Camera always stays on even when i am driving camera still on my dashboard

- Deming, NM, USA

problem #29

Dec 282021

Sierra 1500

  • miles
I own a 2020 GMC Sierra 1500 4-Cyl, Turbo, 2.7 Liter with 20K miles and I owned the truck for almost 2 years. All of a sudden my vehicle started receiving multiple warning messages. While driving I stopped, and when traffic stopped in front of me the engine died all the lights were on warning messages on the dashboard started showing up. Electronic Stability Control, Antilock Braking System, ECM, reduced Engine Power, etc., and the brakes were hard to step on it and the steering wheel hard to turn, I took my foot off the brakes and pressed it again to start. It started but the check engine light was still on, this happened FOUR times already and THREE times while parked when I tried to start, after a few tries giving few minutes intervals, it will start with all the lights on and warning messages on the dashboard start showing up. Electronic Stability Control, Antilock Braking System, ECM, reduced Engine Power, etc., and the brakes were hard to step on it and the steering wheel hard to turn.

- Aventura, FL, USA

problem #28

Jan 162023

Sierra 1500

  • miles
Normal driving conditions vehicle decelerated and warning lights and notification appeared. Warning were -??Service ECS-?? and -??Steering Assist is reduced Drive with care-??. Shut off vehicle for 30 minutes and warnings were no longer present and vehicle drove normally. Happened again 24 hours later. Received email notifications from GMC to arrive within one day. This was a know recall of the previous model year.

- Two Harbors, MN, USA

problem #27

Feb 262021

Sierra 1500

  • 140,000 miles
The contact owns a 2020 GMC Sierra 1500. The contact stated that while driving in the snow, the tire pressure and power steering warning lights illuminated. The vehicle was not diagnosed or repaired. The vehicle was taken to a dealer where it was confirmed that there were no recall or warranties that would cover the repairs for the warning lights. The failure mileage was 140,000.

- Rowlesburg, WV, USA

problem #26

Jan 012022

Sierra 1500

  • miles

A D V E R T I S E M E N T S

I have a lifters problem that the dealership takes more that three weeks to fixed without a loaner car, then i have electrical problems where the truck doesn't start at all without any warning and that's it's dangerous, never now where its going happen

- Fort Worth , TX, USA

problem #25

Sep 242021

Sierra 1500

  • miles
Own a 2020 GMC Sierra AT4 with 13K miles and I owned the truck for 1 year. All of a sudden my vehicle started receiving multiple warning messages. Electronic Stability Control, Antilock Braking System, ECM, reduced Engine Power, etc. I see there was a recall for 2019 GMC Sierra's for the same issues. Why isn't 2020 GMC Sierra's not also part of that recall " It is ridiculous that a brand new truck has these types of serious issues affecting so many vehicles. Why is GMC allowed to continue to sell later model trucks after the 2019 recall with the exact same ESC and Anti-lock Braking system problems "

- Jessup, MD, USA

problem #24

Sep 182021

Sierra 1500

  • miles
Two times while on the freeway the service parking brake and engine lights came on and starting braking. Could not drive over 20 mile an hour. Both times taking to dealer the lights where not on and they could not find anything wrong. I even have video of it happening.

- Pasadena, TX, USA

problem #23

Sep 042021

Sierra 1500

  • miles
Bought 9-4-2020. On 9-4-2021 went start vehicle and no electrical power, battery dead. Will not hold charge to start. Brand new purchased at Morgan GMC in Shreveport Louisiana

- Jackson , MO, USA

problem #22

Dec 142020

Sierra 1500

  • miles
Issue 1: Front left sensor(s), after a rain, car wash and now after an oil change, continuously vibrates the drivers seat and the red light warning stays lite indicating that an obstacle is located near the left front of the truck. This has happened on several occasions and after a time both indicator stop. Issue 2: When traveling on a freeway, twice now, the cruise control suddenly disengaged or decreased mileage, as if it had detected a vehicle in front of us. There was no vehicle within a quarter mile of us front or back, nor any vehicles on the side. No debris in the road either. Usually when the adaptive cruise is set and detects something in front the icons on the dash turn orange and starts to flash. That didn't happen, rather the cruise icon changed to blue in color and the truck slowed. This I would consider a safety risk. Both instances (December 2020 and April 2021) have been reported to a dealership and noted in a file. When the customer care person attempted to get malfunction codes, nothing appeared to be wrong with the vehicle.

- Lake City, FL, USA

problem #21

Jun 122021

Sierra 1500

  • miles
Service ESC, Service Power Steering, antilock brakes disabled all flashed on information center of vehicle. Service engine light, antilock brake light, ESC, low battery all illuminated. Vehicle would not start - try to start it would go through all issues on information center. This is the same ESC issue described for 2019 Silverado and GMC Sierras.

- Lowell, MI, USA

problem #20

May 222021

Sierra 1500

  • miles
The display for the backup camera and infotainment system became blank. Other owners have the same complaint. This is a serious safety issue because I was backing up when it went blank.

- Vallejo, CA, USA

problem #19

Apr 302021

Sierra 1500

  • 10,300 miles
It was fine and we drove to our neighbor, parked about 15 mins. When we started the truck to turn back, the steering was super heavy, with 2 messages pop up on the dashboard: Services ESC, and service power steering drive with care. Tried several times to re-start the truck, it's keep the same. In our neiborhood, parrot tulip view, pflugerville, tx 78660. Raining all night, not sure if it's related to the weather.

- Pflugerville, TX, USA

problem #18

Feb 252021

Sierra 1500

  • 8,800 miles
When stationary and preparing to start vehicle intermittently see "service steering column lock" message appears and disappear once vehicle is started. This was previously supposed to be addressed with service bulletin 20-na-21 however being told by service department that vehicle has all current updates applied a year ago, including the one that should of addressed the issue. Told that the vehicle history shows records of past "loss of communication to dic" but as they can't immediately reproduce no action was taken.

- Tyler, TX, USA

problem #17

Dec 142020

Sierra 1500

  • 2,339 miles
On December 14, 2020 my Sierra with 2339 miles displayed, at startup, the power steering was out, to drive with care. Also displayed service ESC and traction control failures. I drove with much difficulty, without power steering, ten miles to the nearest GMC dealership, lafontaine in highland, mi. I picked up the vehicle on December 29, 2020 with an additional 60 miles. The service personnel said they were unable to duplicate the problem, therefore no repairs were made. Lafontaine had contacted General Motors tech center who offered no solutions other than checking the battery and wiring harness connections. The problem has not reappeared in the fifteen days since I picked up my vehicle.

- White Lake, MI, USA

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