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Fuel systemPart report

2021 Chevrolet Silverado 3500 Fuel system Problems

Complaints
5about this part
Share
12%of 41 total for the year
Median mileage
15,521miles
Trend
Not enough dataFewer than 15 complaints, too few for a reliable trend.

NHTSA recorded 5 complaints about the fuel system of the 2021 Chevrolet Silverado 3500, 12% of the 41 complaints for this model year. Where a mileage was given, the median is 15,521 miles. 1 a fire, according to the filers.

Fewer than 15 complaints name this part, so treat the figures as a rough indication only.

Example complaints

Selected from NHTSA records; personal details are removed. They are consumer reports, not findings.

“My 2021 chevy 3500hd diesel had the engine light come on and the service emissions system popped up in the info screen. It said in so many miles speed would be limited. I took it to the dealer and they said the def tank would need replaced because the tank wiring connector overheated and would cost me over $2k.”

NHTSA complaint #11716547, filed 2026-02

“Injector #4 connector harness issue- Known issue on the 6.6L duramax. Driving with my children for Christmas pickup and power reduction occurred while passing another car on the road. Causing us to hit the breaks as the truck wouldn’t allow us to pass timely. Known harness issue by GM and instead of covering I had to pay to have a new connector spliced in. Multiple warning lights. Check engine, Emissions warning, Reduced power, Traction control, parking brake”

NHTSA complaint #11632370, filed 2024-12

“Check engine light came on followed almost immediately with an Onstar warning to service the engine and transmission within 7 days. Took truck to dealer. They diagnosed problem was fuel system contamination. Hole was found on the inner mesh liner of the fuel filter which allowed water and a sludge like material to get into the fuel system.”

NHTSA complaint #11472736, filed 2022-07

“Service engine light kept coming on the dash, and the code came back to a faulty DEF heater. My truck had a reduced power countdown on the dash indicating the truck was going go to into limp mode after x amount of miles. On warmer days the code would go away and there would be no reduced power. The vehicle was diagnosed at a GM dealership and confirmed the DEF heater was bad, but was notified that there is a bulletin with GM for this issue occurring in many other diesel trucks. …”

NHTSA complaint #11719345, filed 2026-02

“The contact owns a 2021 Chevrolet Silverado 3500. The contact stated that while driving at approximately 45 MPH, he noticed smoke coming from the rear of the vehicle. The contact mentioned that the smoke would become more aggressive as the accelerator or brake pedal was depressed. The vehicle caught on fire however the origin was unknown. The contact and his family exited the vehicle safely and discovered unknown fluid emitting from the rear of the vehicle. The contact used a fire extinguisher to attempt to extinguish the fire however the fire kept returning a total of 4 times. …”

NHTSA complaint #11605095, filed 2024-07, 15,521 miles

Related service bulletins

Fuel system: other model years

YearComplaintsShare of year
202518%
202448%
202316%
2021512%
2020512%
2019418%
2018526%
2017215%
20161122%
20151529%
2014330%
2013415%
2012626%
2011621%
200826%
2007513%
200636%
2005817%
2004717%
2003717%
2002816%
2001710%
200011%
199949%
19981015%
1997711%

Other parts of the 2021 Chevrolet Silverado 3500

Electrical system
13 complaints
Transmission and drivetrain
7 complaints
Latches, locks and linkages
6 complaints
Body and structure
6 complaints
Brakes
5 complaints
Other or unknown
5 complaints
Engine
3 complaints
Air bags
2 complaints
Steering
2 complaints
Exterior lighting
1 complaints
Forward collision avoidance
1 complaints
Lane departure
1 complaints

← All problems reported for the 2021 Chevrolet Silverado 3500

About this data. Data from NHTSA (ODI) complaints, recalls, TSBs and investigations, updated Oct 31, 2026. Complaints are unverified consumer reports and may be duplicated or inaccurate.

To check a specific vehicle for open recalls, use its VIN at nhtsa.gov/recalls. Methodology