Is the 2020 Gmc SIERRA 3500 reliable?

The 2020 Gmc SIERRA 3500 has 72 complaints filed with NHTSA (2.9x the segment average). Our reliability verdict: avoid. Most common issue: TRANSMISSION problems.

What are common problems with the 2020 Gmc SIERRA 3500?

Top problems: TRANSMISSION (19 complaints, avg repair $500); ELECTRICAL (9 complaints, avg repair $500); BRAKES (7 complaints, avg repair $500). Issues typically appear around 50K miles.

Are there any recalls on the 2020 Gmc SIERRA 3500?

Yes, there are 8 recall(s): LATCHES/LOCKS/LINKAGES:HOOD:LATCH, SEAT BELTS, AIR BAGS:SIDE/WINDOW:CURTAIN:INFLATOR, SEAT BELTS:PRETENSIONER, STRUCTURE:BODY:HOOD, LATCHES/LOCKS/LINKAGES:TAILGATE:LATCH, POWER TRAIN:AUTOMATIC TRANSMISSION:CONTROL MODULE:SOFTWARE, POWER TRAIN:AUTOMATIC TRANSMISSION:CONTROL MODULE:SOFTWARE. Contact any Gmc dealer to verify if recalls have been completed on your specific vehicle.

How much does it cost to insure a 2020 Gmc SIERRA 3500?

Estimated US average full-coverage insurance for the 2020 Gmc SIERRA 3500 is approximately $1,607/year (sedan-midsize class). Actual quotes vary heavily by state, driver age, driving record, and credit — see the interactive insurance estimator on this page for state-specific pricing.

2020 Gmc SIERRA 3500

Problems, Recalls & Reliability Report

Avoid This Year

Quick Summary

The 2020 Gmc SIERRA 3500 has 72 owner complaints filed with NHTSA — that's 2.9x the segment average of 25. The most common issue is transmission problems (26% of all complaints), specifically: the computer lite up the dash and reduced power, plus took the trailer brakes off line. this happened while loaded. to reset the system you have to pull over and turn the vehicle off. this happens 2-3 times per day. this was a problem at 600 miles. the transmission shifted from 10 gear to 5th g. There are 8 recalls issued for this model year. ⚠️ 4 fire reports filed.

4 fire reports 5 crash reports 4 injuries

Total Complaints

Recalls Issued

—/5

Safety Stars

2.9x

vs Segment Avg

Known Problems(top 5 of 8)

TRANSMISSION

19 complaints

26%

• The computer lite up the dash and reduced power, plus took the trailer brakes off line. This happened while loaded. To reset the system you have to pull over and turn the vehicle off. This happens 2-3 times per day. This was a problem at 600 miles. The transmission shifted from 10 gear to 5th g
• The exhaust system is directed to the rear of the vehicle and when towing causes extreme heat to build on the item being towed, in my case a 5th wheel camper. The heat has melted the trim on my camper and is a potential fire hazard.
• Rear tires locking up out of no where almost made me jack knife.

Typical onset: 50K miles Est. repair: $500💥 3 crashes

“The computer lite up the dash and reduced power, plus took the trailer brakes off line. This happened while loaded. To reset the system you have to pull over and turn the vehicle off. This happens 2-3 times per day. This was a problem at 600 miles. The transmission shifted from 10 gear to 5th g”

— NHTSA complaint filing

When Problems Appear on the 2020 Gmc SIERRA 3500

Based on 12 owner complaints that included an odometer reading. Median mileage at time of complaint: 29K miles. Most complaints cluster in the 0-30K miles range.

Overall complaint distribution by mileage

0-30K

30-60K

60-100K

100-150K

150-200K

200K+

Mileage figures are self-reported by owners in NHTSA complaint filings. Peak bucket = the mileage range with the most complaints for that component; it reflects when owners noticed and reported problems, not necessarily when the fault first occurred.

Recalls (8)

LATCHES/LOCKS/LINKAGES:HOOD:LATCH12/03/2020

General Motors LLC (GM) is recalling certain 2020 Chevrolet Silverado 2500 and 3500 and GMC Sierra 2500 and 3500 vehicles. The hood-latch striker wires may not have been heat-treated properly, possibly causing them to fracture.

Risk: If a striker wire fractures, the hood may open unexpectedly while driving, increasing the risk of a crash.

Fix: GM will notify owners, and dealers will replace the hood assembly, free of charge. The recall began April 13, 2020. Owners may contact Chevrolet customer service at 1-800-222-1020 or GMC customer service at 1-888-988-7267. GM's number for this recall is N192284960.

Estimated Insurance Cost for 2020 Gmc SIERRA 3500

Estimate only, not a quote. Modeled from NAIC + HLDI averages for a hypothetical 35-year-old driver with clean record + full coverage. Your actual quote depends heavily on your age, driving history, credit, ZIP code, and insurer.

Your state (affects local premium average)

Full coverage / year

$1,607

Full coverage / month

$134

Liability only / year

$611

vs US avg

-4%

How this estimate is calculated

US base full-coverage premium$1674

× state (US)1.00x

× vehicle class (sedan-midsize)0.96x

× theft risk1.00x

× safety rating1.00x

× vehicle age1.00x

= Full coverage estimate$1607

Coverage assumed: 100/300/100 liability + comprehensive/collision, $500 deductibles. Data sources: NAIC 2024 + HLDI loss studies.

Maintenance & Warranty

Recommended Gmc SIERRA 3500 Service Intervals

Oil change

8K mi / 12 mo

Tire rotation

8K mi

Brake fluid

36 months

Transmission fluid

45K mi

Engine coolant

150K mi

Spark plugs

100K mi

Cabin air filter

23K mi

Engine air filter

45K mi

Differential (AWD/4WD)

45K mi

Uses GM Oil Life System. Full-size trucks may have shorter differential and transfer case intervals if used for towing.

"Severe service" conditions (heavy towing, extreme temps, city stop-and-go) typically halve these intervals. Always consult your vehicle's owner's manual for the authoritative schedule.

Gmc New-Vehicle Warranty Coverage

Bumper-to-bumper (basic)

3 yr / 36K mi

Powertrain

5 yr / 60K mi

Hybrid/EV battery

8 yr / 100K mi

Corrosion (rust perforation)

6 yr / 100K mi

Roadside assistance

5 yr / 60K mi

These are the terms for a new Gmc. If you're buying a used 2020 SIERRA 3500, remaining coverage is usually pro-rated from the vehicle's original in-service date. Not all coverage transfers between owners — check with a Gmc dealer for VIN-specific remaining warranty.

Estimated Repair Costs

TRANSMISSION(~50K mi)

$500

ELECTRICAL(~50K mi)

$500

BRAKES(~50K mi)

$500

ENGINE(~50K mi)

$500

OTHER(~50K mi)

$500

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

🔍 Pre-Purchase Inspection Checklist

Based on 72 owner complaints for this specific year, here's what to check or ask about:

☐
TRANSMISSION: The computer lite up the dash and reduced power, plus took the trailer brakes off line. This happened while loaded. To reset the system you have to pull over and turn the vehicle off. This happens 2-3 times per day. This was a problem at 600 miles. The transmission shifted from 10 gear to 5th g
Typically appears around 50K miles. Repair cost ~$500
☐
ELECTRICAL: PROGRESSIVE PAUSE STARTS WHEN STARTING VEHICLE. AFTER A FEW WEEKS OF PAUSE STARTING VEHICLE HAD NO POWER AT ALL. TOWED IT TO DEALER THEY REPLACED A BAD BATTERY. PAUSE START CONTINUED AND AFTER 4-5 WEEKS VEHICLE WOULD NOT START. COULDN'T TURN PARK BREAK OFF. THERE WAS POWER (LIGHTS IN DASH CAME
Typically appears around 50K miles. Repair cost ~$500
☐
BRAKES: The computer malfunctions. It is available for inspection. The computer lights up and causes failure in the trailer brakes. Glenn Polk the dealership in Sanger Texas has been working on a fix but has yet to come up with one. I have spoken with General Motors Representatives several time trying to
Typically appears around 50K miles. Repair cost ~$500
☐
ENGINE: The computer lights up the dash reducing power and turning off power to trailer brakes. This has almost caused an accident on several occasions . It happens a couple of times per trips. This vehicle has been in the shop a couple of times per month since it was put into service. Glenn Polk Chevr
Typically appears around 50K miles. Repair cost ~$500
☐
RECALLS: Verify all 8 recalls have been completed — free at any Gmc dealer
☐
General: Get a pre-purchase inspection from an independent mechanic ($100-$200)