Why Is the 2021 GMC Sierra 1500 So Unreliable?

As far as full-size pickup trucks go, the 2021 GMC Sierra 1500 has all of the requirements to be great. Aside from offering a luxury interior, the Sierra has various engine options and impressive safety tech. Despite this, a new survey conducted by Consumer Reports found that the GMC Sierra 1500 is one of the least reliable pickup trucks currently available for sale.

The 2021 GMC Sierra 1500 excels during road tests

A photo of the GMC Sierra Denali outdoors.
GMC Sierra Denali | GMC

U.S. News recently got to test a 2021 GMC Sierra 1500 and found that the full-size truck has few faults on the surface. As you’d expect from a luxury-oriented truck, the Sierra excelled during testing with its smooth ride quality. The excellent driving experience comes from the GMC’s Magnetic Ride Control, which senses the road ahead and adjusts the magnetic shocks in response. On top of that, the Sierra 1500 was noted as having a very spacious and quiet cabin. The infotainment system was also noted as being very user-friendly.

In terms of engine options, the Sierra 1500 has plenty to offer. Although the standard 285-hp naturally-aspirated V6 won’t win awards for speed or towing capacity, there are two available V8’s. The first is a 5.3-liter naturally-aspirated engine that produces 355 hp and 383 lb-ft of torque. The second and most powerful option is a naturally-aspirated 6.2-liter engine. Max output comes in at 420 hp and 460 lb-ft of torque. The result is that the GMC is not only highly refined but incredibly capable.

Where does the Sierra begin to fail?

A photo of the GMC Sierra Denali outdoors.
GMC Sierra Denali | GMC

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Despite the GMC Sierra 1500’s greatest assets, Consumer Reports claims that the truck seems to struggle in the real world. Much like the 2021 Chevy Silverado covered in the same report, the Sierra 1500 struggles in critical areas. The worst trouble areas are the Sierra’s brakes, power equipment, and in-car electronics. Thankfully for GMC, previously reported issues found in the transmissions and drive system have reportedly subsided.

Given how large the GMC Sierra 1500 is, having faulty brakes certainly doesn’t help. On top of that, Sierra owners have consistently reported having poor brakes since the 2014 model. Although Consumer Reports does not state exactly which brake issues plague the 2021 Sierra, the category covers components such as the calipers, rotors, and master cylinder, to name a few.

Given the low scores awarded to the GMC Sierra 1500 for both power equipment and in-car electronics, the tech features don’t seem to be very reliable either. These sections cover the infotainment screen and vital components such as the instrument cluster, cameras, and sensors.

Thankfully, it seems that engine reliability has improved slightly since the 2020 model. While the scores are far from ideal, the Sierra seems to be on the right path. Despite this, the Sierra 1500 remains one of the least reliable trucks tested by Consumer Reports.

Is it still worth buying?

A photo of the GMC Sierra Denali outdoors.
GMC Sierra Denali | GMC

If you’re contemplating pulling the trigger on a brand-new 2021 GMC Sierra 1500, chances are you’ll be better off waiting for an updated model. Given Consumer Reports’ tracking of the Sierra over the years, it seems the model is heading toward the right direction in terms of reliability.

However, if you want a full-size pickup truck today, Consumer Reports rated both the Ford F-150 and the Ram 1500 far more favorably than the troubled GMC.