2021 Gmc SIERRA 2500

Problems, Recalls & Reliability Report

Average

Quick Summary

The 2021 Gmc SIERRA 2500 has 60 owner complaints filed with NHTSA — that's 0.8x the segment average of 80. The most common issue is transmission problems (18% of all complaints), specifically: the owns a 2021 gmc sierra 2500. the contact stated while driving 70 mph, the rpm revved up to 6,000 rpm. additionally, the vehicle lost motive power. the vehicle was taken to the dealer, who informed the contact that the transmission needed to be replaced. the vehicle was not repaired. the manufact. ⚠️ 2 fire reports filed.

2 fire reports 5 crash reports 1 injury

Total Complaints

Recalls Issued

—/5

Safety Stars

0.8x

vs Segment Avg

Known Problems

TRANSMISSION

11 complaints

18%

• The owns a 2021 GMC Sierra 2500. The contact stated while driving 70 MPH, the RPM revved up to 6,000 RPM. Additionally, the vehicle lost motive power. The vehicle was taken to the dealer, who informed the contact that the transmission needed to be replaced. The vehicle was not repaired. The manufact
• The transmission started lurching and surging power while driving
• The contact owns a 2021 GMC Sierra 2500. The contact stated while driving approximately 70 MPH, the vehicle lost motive power. The contact stated that the message “Vehicle will not Exceed 50 MPH" was displayed. The vehicle was taken to a dealer and remained for over four months after being diagnosed

Typical onset: 50K miles Est. repair: $500💥 1 crashes

“The owns a 2021 GMC Sierra 2500. The contact stated while driving 70 MPH, the RPM revved up to 6,000 RPM. Additionally, the vehicle lost motive power. The vehicle was taken to the dealer, who informed the contact that the transmission needed to be replaced. The vehicle was not repaired. The manufact”

— NHTSA complaint filing

LIGHTING

9 complaints

15%

• Passenger headlight light fills up with moisture resulting in the HID module filling up with water and shorting out. The high beam starts flashing when you try to use your turn signal and eventually the headlights completely stop working. Is a known problem, but GM won’t do anything to help if you’r
• The driver side headlamp stopped working, Condensate buildup may be a contributing factor. No accident and vehicle is meticulously maintained. No reason for lamp seals to be damaged or wear. Barely three years old and requires a replacement at $1400 for the part and another $1000 in labor. Out
• 3 year old truck. The left headlight enclosure gained water and caused the whole headlight system to have issues. Water caused the Headlights to Flash high beams (both), turn off and blinkers not to work. This defect the whole side that is effective. This can cause other drivers or the owner to ha

Typical onset: 50K miles Est. repair: $500

“Passenger headlight light fills up with moisture resulting in the HID module filling up with water and shorting out. The high beam starts flashing when you try to use your turn signal and eventually the headlights completely stop working. Is a known problem, but GM won’t do anything to help if you’r”

— NHTSA complaint filing

ENGINE

7 complaints

12%

• THE TRUCK IS PARKED AT DEALERSHIP
• Diesel Exhaust Fluid tank, high pressure
• The contact owns a 2021 GMC Sierra 2500. The contact stated that the vehicle was equipped with an engine block heater that he plugged into the vehicle when the weather was below 32 degrees to start the vehicle. The contact stated that he noticed that the engine block heater was causing the GFCI outl

Typical onset: 50K miles Est. repair: $500

“THE TRUCK IS PARKED AT DEALERSHIP”

— NHTSA complaint filing

ELECTRICAL

6 complaints

10%

• While driving the entire dash cluster (speed,rpm etc) turns off entirely, reloads as if truck is just starting with all lights coming off and on, needles cycling max/min. Unable to recreate on command, multiple others reported same issue with no cause/cure listed.
• The harness that hooks to bumper plug for trailer lighting is not completely water tight. Allows water in and creates buildup that weakens the connection as well as allows the plug wire connection to snap out and push out from the pin. Further inspection it was causing a short in the system. I atte
• Smog system check and Engan warning light keeps come on.

Typical onset: 50K miles Est. repair: $500💥 1 crashes

“While driving the entire dash cluster (speed,rpm etc) turns off entirely, reloads as if truck is just starting with all lights coming off and on, needles cycling max/min. Unable to recreate on command, multiple others reported same issue with no cause/cure listed.”

— NHTSA complaint filing

BRAKES

5 complaints

• Brake pads have excessive squealing. Squealing implies incorrect pressure to rotor to stop the vehicle, which highly concerns me as an operator. According to the dealer where I reported the issue, there is a technical bulletin that approves replacement of the brake pads for free if reported in fir
• The contact owns a 2021 GMC Sierra 2500. The contact stated while approaching a stop sign and depressing the brake pedal, the brakes were squeaking. The vehicle was taken to the dealer and the contact was informed that the brake pads needed to be replaced. The brakes on the vehicle were replaced but
• Seems to be a known problem according to a google search but brake fluid leaking from brake pedal onto drivers floor mat. Seems to be a bad brake booster according to google and happening for some at a few weeks to a couple months old in the newer ones. I noticed first on my truck around 58,000 mil

Typical onset: 50K miles Est. repair: $500

“Brake pads have excessive squealing. Squealing implies incorrect pressure to rotor to stop the vehicle, which highly concerns me as an operator. According to the dealer where I reported the issue, there is a technical bulletin that approves replacement of the brake pads for free if reported in fir”

— NHTSA complaint filing

Estimated Repair Costs

TRANSMISSION(~50K mi)

$500

LIGHTING(~50K mi)

$500

ENGINE(~50K mi)

$500

ELECTRICAL(~50K mi)

$500

BRAKES(~50K mi)

$500

Estimates based on average reported repair costs. Actual costs vary by location, shop, and severity.

🔍 Pre-Purchase Inspection Checklist

Based on 60 owner complaints for this specific year, here's what to check or ask about:

☐
TRANSMISSION: The owns a 2021 GMC Sierra 2500. The contact stated while driving 70 MPH, the RPM revved up to 6,000 RPM. Additionally, the vehicle lost motive power. The vehicle was taken to the dealer, who informed the contact that the transmission needed to be replaced. The vehicle was not repaired. The manufact
Typically appears around 50K miles. Repair cost ~$500
☐
LIGHTING: Passenger headlight light fills up with moisture resulting in the HID module filling up with water and shorting out. The high beam starts flashing when you try to use your turn signal and eventually the headlights completely stop working. Is a known problem, but GM won’t do anything to help if you’r
Typically appears around 50K miles. Repair cost ~$500
☐
ENGINE: THE TRUCK IS PARKED AT DEALERSHIP
Typically appears around 50K miles. Repair cost ~$500
☐
ELECTRICAL: While driving the entire dash cluster (speed,rpm etc) turns off entirely, reloads as if truck is just starting with all lights coming off and on, needles cycling max/min. Unable to recreate on command, multiple others reported same issue with no cause/cure listed.
Typically appears around 50K miles. Repair cost ~$500
☐
General: Get a pre-purchase inspection from an independent mechanic ($100-$200)