2020 GMC Sierra 1500 · symptom sheet
Check engine light or misfire
- 84owner reports
- 74,000median miles
- $9,200median quote
- 0involved a crash
Newest report Sep 24, 2026 · checked Oct 2, 2026
315 of the 468 complaints on this car are about the engine. 84 of those describe misfire. Only engine failure is reported more often on this car.
Tick what matches of 84 reports
Misfire on other Sierra 1500 years
Report counts are for each model year on its own, so a newer car has had less time to collect them. Model years with too few reports of it for a sheet: 2014, 2015, 2016, 2017, 2018, 2025, 2026.
What this problem usually is
These reports start with the check engine light. Many describe the engine running rough or shaking at idle, a P0300-series code, or a catalytic converter code. A worrying number say the light was flashing. Owners often list ignition coils or spark plugs already replaced, and the light coming back afterward.
What got replaced
Owners who name the part that was replaced mention the sensor (4 reports), the ignition coils (3 reports) and the spark plugs (3 reports).
Recalls and investigations
2 recalls on the engine cover the 2020 model year. A recall on the same system isn't always the same failure, so read the defect text.
The battery positive (B+) cable rings may have been manufactured with excessive glue, potentially causing an intermittent electrical connection between the B+ cable and alternator.
The fuel pump may be missing a pressure regulator, allowing for over-pressurization of the fuel system.
All 12 recalls on the 2020 GMC Sierra 1500, with the owner complaints on each recalled system
NHTSA investigations into the engine on the Sierra 1500
Loss of motive power due to engine failure post recall remedy. Open.
Loss of motive power due to engine failure post recall remedy. Closed aug 20, 2026.
Loss of motive power due to engine failure. Open.
Loss of motive power due to engine failure. Closed oct 23, 2025, led to recall 25V-274.
Pedestrian alert sounds. Closed aug 7, 2023, led to recall 22V-063.
Non-crash engine compartment fires. Closed sep 8, 2008, led to recall 08V-441.
Non-crash engine compartment fires. Closed jun 12, 2008.
What owners paid
17 of the 84 reports quote a price. Each dot is one quote. The middle half runs $5,100 to $10,000.
When it happens
The middle half of failures fell between 42,000 and 99,500 miles, from the 48 reports that gave a mileage.
Is this a known problem?
The manufacturer has sent NHTSA 41 service bulletins or notices for the 2020 GMC Sierra 1500 that deal with this problem. Newest first.
Federal rules make a manufacturer send NHTSA a copy of any notice about a defect that goes to more than one dealer or owner. Most of these are service bulletins, the repair instructions manufacturers send to dealers. NHTSA generally leaves safety recall bulletins out of this file, and recalls are listed separately.
This bulletin advises the tech that the Exhaust Roller Follower may be the issue with the engine Ticking noise, misfire or rough run and what to replace if found the cause.
This technical bulletin provides repair information to correct a customer concern of Evaporative DTCs P0442, P0446, P0455 or P0449, Caused by Dust Intrusion into the Evaporative Canister.
This service bulletin provides repair information for Engine Wire Harness Chafing to correct customer concerns of IPC Gauges Sweep, IPC Warning Message, SES/Check Engine/MIL, No Start/ No Crank, Runs Rough, Stalls, Reduced Engine Power, Various DTCs.
This Preliminary information communicates the possibility of DTC P30BF failing on low mile vehicles due to the possibility of the cylinder 1/2 sliding barrel binding on intake camshaft.
37 more on the 2020 GMC Sierra 1500 page.
What owners wrote
“Lifter failed due to AFM system. Cyl 8 misfire due to oil fouling. The onboard computer got confused and would not release the parking brake until repeated attemtps to release it. 5.3L V8 2020 model year 115250 miles. Isn't this the same problem as the 2021 and newer engines? 8spd transmission. AFM failure. $9k repair.”
Filed Sep 7, 2026 · 115,250 miles
“The truck starting making a ticking noise within 24 hours the check engine light was on and it starting shuttering. I got it to the dealership were they informed me of lifters failure, and catastrophic engine failure. Dealer is recommending replacing engine since it's a 2020 and not part of recall.”
Filed Aug 4, 2026
“Truck started to vibrate and loud tick sound, CEL for misfire and traction control. Hard shifting until I could pull to a safe area to call for a tow. Around 76k miles on the truck when it happened.”
Filed Jan 20, 2026 · 76,000 miles
“My 6.3l v8 Started having a slight misfire while driving. Took vehicle to a mechanic and was advised to change the spark plugs, changed spark plugs, spark plug wires, and ignition coil packs while still experiencing sudden misfires while driving. Starting to consider the 6.2L L87 collapsing cylinder issue.”
Filed Aug 26, 2025
Should you keep driving it?
This page can't tell you that. 0 of 84 reports involved a crash. Owners who file are the ones who had a bad experience, and nobody checks their reports. If the problem affects steering, braking, power or a fire risk, treat it as a safety fault and have it inspected before a long or high-speed drive.
File your own report with NHTSA. Complaint counts are how a problem gets an investigation. How reports land on this sheet.
Guide Which lights mean pull over now? Warning lights by color and urgency
Other problems on this car
- Engine failure, knocking or rod bearing 103 reports
- Engine stalls or loses power while driving 68 reports
- Brakes grind, pulse or wear early 53 reports
- Power steering cuts out or goes heavy 25 reports
- Transmission shudders, slips or shifts hard 25 reports