8.5

pretty bad
Crashes / Fires:
0 / 0
Injuries / Deaths:
0 / 0
Average Mileage:
3,417 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 miscellaneous problems

miscellaneous problem

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2020 GMC Sierra 1500 Owner Comments

problem #15

Mar 092022

Sierra 1500

  • miles

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

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 #14

Nov 032023

Sierra 1500

  • miles
Rear window leak causing whole inside back to get soaked. Have paid hundreds of dollars to have sealed didn-??t work. New window didn-??t work it still leaks. It-??s going to cause interior to mold and body to rust. Dealership and glass business both say it-??s body issue and they have seen many GMC and Chevrolets with this issue. Google show 1000s with same problem.

- West Lafayette, IN, USA

problem #13

Dec 092023

Sierra 1500

  • miles
Rear Window Leaks due to failed sealing at the factory. If not fixed will ruin interior components and possibly rust. Yes No

- Jerome, ID, USA

problem #12

Dec 122023

Sierra 1500

  • miles

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

The rear window was leaking a substantial amount of water soaking the back seat. Had the service bulletin done, which did not work. Then under further inspection found cracks in the rear power window track. Dealer told me GM would not cover replacement because it was out of the 3 year warranty. Then was told it would cost me 1200 dollars to replace. GM should cover this because it will lead to black mold.

- Cochranvile, PA, USA

problem #11

Nov 082022

Sierra 1500

  • miles
Once vehicle is put in park, the control panel comes and reads, -??shift in park and radio and head lights stays on as well-??. I exit the vehicle and it continues to display the mention above. I-??ve restarted the vehicle and put it back in park still the -??shift in park-??, stays on. I exit the vehicle and monitored the vehicle for approximately 5 minutes and finally turned off. This never happened before, I-??m afraid it may stay on one of these days and run the battery down.

- Window Rock, AZ, USA

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problem #10

Sep 042020

Sierra 1500

  • miles
Rear window (the one that faces straight back towards bed of truck) is leaking-?? Haven-??t taken it in to dealership for repair because I-??ve exceeded mileage so truck is no longer under warranty-?? Not sure how long it-??s been leaking but I-??ve recently noticed that water stains (runs) on the inside of this window after rains, washes, etc-??

- Corpus Christi , TX, USA

problem #9

May 142022

Sierra 1500

  • miles

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

Vehicle engine went out on truck.

- Cache, OK, USA

problem #8

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 #7

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 #6

Feb 242021

Sierra 1500

  • 20,000 miles
Dangerous visibility hazard when backing up vehicle at night. Infotainment screen switches to "full brightness" when backup camera is activated, resulting in blinding light to driver. Driver can not backup safely without physically covering the screen to regain visibility. Screen brightness reflects off all 4 windows, windshield and back glass. Side mirrors are unusable in this condition. There was a fix for this issue on previous GM models, (prior to 2018), however no fix for 2019 - present

- Corpus Christi, TX, USA

problem #5

Jul 152020

Sierra 1500 4-cyl

  • 7,000 miles

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

After vehicle sits idle for a while, the vehicle makes a high pitch whistling sound on startup that last for approximately minute of driving.

- Princeton, TX, USA

problem #4

Jun 192020

Sierra 1500 6-cyl Diesel

  • 4,000 miles
Navigation states to turn right when it should be left or vice versa. This was a problem on the 2016-2017 models also.

- Kennewick, WA, USA

problem #3

Apr 012020

Sierra 1500 8-cyl

  • 10 miles
Can not see anything backing up in the dark because of backup camera. The picture on the screen is grainy and washed out so all you see are blobs of nothing.

- Millston, WI, USA

problem #2

Feb 102020

Sierra 1500

  • 144 miles
Brand new truck. Stuck at the gym in the middle of the night truck wont start. The interior lights, head lights, and radio wont shut off. Vehicle wont start. I'm assuming the battery was drained because interior lights, exterior lights, radio, wont shut off. Has to be some kind of electrical malfunction. Waiting on GM roadside.

- Mesa, AZ, USA

problem #1

Jan 212020

Sierra 1500

  • 1,000 miles
The backup camera is entirely too bright at night. It is nearly impossible to see the mirrors due to the brightness

- Lafayette, LA, USA

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