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2021 Chevrolet Silverado 2500

Owner reports · Recalls · Investigations

Similar to other model years

Owner complaints for the 2021 Chevrolet Silverado 2500 do not stand out strongly from the model-year median of 81.

About this comparison →

When problems were reported

Mileage at the reported incident

Limited mileage data: 17 of 84 reports include usable mileage. There isn’t enough coverage to show a useful chart.

NHTSA’s mileage field refers to the reported incident, not necessarily the filing date. This shows report counts, not the likelihood of a failure.

What to inspect

Issues worth paying extra attention to based on owner reports.

  • Power Train. Review the 28 owner reports in this category and discuss these concerns during a pre-purchase inspection. Read reports →
  • Electrical System. Review the 17 owner reports in this category and discuss these concerns during a pre-purchase inspection. Read reports →
  • Service Brakes. Review the 12 owner reports in this category and discuss these concerns during a pre-purchase inspection. Read reports →

NHTSA owner reports · September 18, 2026 snapshot.

2 crash reports1 fire reports2 injury reports

Power Train complaints

28 reports
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Mileage unknown · Aug 22, 2024
Power Train

The transmission has a defect. While towing 8,000lb trailer going up a small grade, the truck shuddered then immediately downshifted violently, causing the truck to skid and almost jack-knifing the truck and trailer. . The dealership has confirmed the issue as a valve body failure in the transmission. The dealership has the veh…

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The transmission has a defect. While towing 8,000lb trailer going up a small grade, the truck shuddered then immediately downshifted violently, causing the truck to skid and almost jack-knifing the truck and trailer. . The dealership has confirmed the issue as a valve body failure in the transmission. The dealership has the vehicle for diagnosis and repair. No codes or warnings were displayed at the time of the incident. The dealership updated the software which produced a powertrain failure code, the valve body failed.

NHTSA ODI #11610341

94,000 miles · Feb 20, 2024
Power Train

The contact owns a 2021 Chevrolet Silverado 2500. The contact stated while driving at various speeds, the vehicle downshifted from 8th to 7th gear or from 8th to 6th gear, and the wheels locked up, causing the contact to lose control of the vehicle. There was no warning light illuminated. The contact was able to regain control o…

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The contact owns a 2021 Chevrolet Silverado 2500. The contact stated while driving at various speeds, the vehicle downshifted from 8th to 7th gear or from 8th to 6th gear, and the wheels locked up, causing the contact to lose control of the vehicle. There was no warning light illuminated. The contact was able to regain control of the vehicle and continued driving. The contact stated that the failure recurred several times while driving. The contact stated that the safety risk was more severe while towing a trailer because the failure caused the trailer to fishtail while driving. The contact stated that he had pulled to the side of the road on one occasion. The vehicle was taken to the dealer but was not diagnosed or repaired. The contact related the failure to TSB Number: 21-NA-275. The manufacturer was notified of the failure, but no assistance was provided. The failure mileage was approximately 94,000.

NHTSA ODI #11572953

Mileage unknown · Jan 19, 2024
Power Train

The transmission fluid line that goes from the radiator to the cooler came apart at the crimp were the rubber and metal tube connect, this allowed all the transmission fluid to spray all over the motor while driving and leaving us stranded.

NHTSA ODI #11566508

Mileage unknown · Jan 5, 2024
Power Train

While driving down the road at 40mph the crimp connection for the transmission cooling line came apart and spilled all my transmission fluid out the power hose and left me stranded in the middle of the road.

NHTSA ODI #11563860

110,000 miles · Oct 11, 2023
Power TrainTrailer Hitches

The contact owns a 2021 Chevrolet Silverado 2500. The contact stated while driving uphill at an undisclosed speed with a trailer hitched to the vehicle, the vehicle downshifted inadvertently, which caused the trailer to fishtail. The contact stated that he lost control of the vehicle, and he was able to slowly regain control of …

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The contact owns a 2021 Chevrolet Silverado 2500. The contact stated while driving uphill at an undisclosed speed with a trailer hitched to the vehicle, the vehicle downshifted inadvertently, which caused the trailer to fishtail. The contact stated that he lost control of the vehicle, and he was able to slowly regain control of the vehicle. The contact stated that the failure had been recurring while driving. The vehicle was taken to an unknown dealer, where the cause of the failure could not be determined. The vehicle was not repaired. The manufacturer was not notified of the failure. The failure mileage was approximately 110,000. The VIN was not available.

NHTSA ODI #11549447

Mileage unknown · Apr 24, 2023
Electrical SystemPower Train

2021, Chevrolet Silverado 2500 HD, Crew-Cab, 6.6L Gas Engine. At @ 25k miles, the "Service 4WD" light came on dash. It later started a grinding noise/sound within the front axle transfer case. Was told they had a problem with moisture intrusion into the transfer case and it would cause corrosion to sensor. Truck was taken to …

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2021, Chevrolet Silverado 2500 HD, Crew-Cab, 6.6L Gas Engine. At @ 25k miles, the "Service 4WD" light came on dash. It later started a grinding noise/sound within the front axle transfer case. Was told they had a problem with moisture intrusion into the transfer case and it would cause corrosion to sensor. Truck was taken to dealership and in shop for @ 1 week or so. After repair was completed, less than 3k miles later, it happened again. Same problem ("Service 4WD"), same noises, same diagnoses. Truck was taken back to the dealership. This time, repairs were more extensive and the wiring harness was replaced. I was traveling with work yesterday (34,458 miles on truck now) and the "Service 4WD" light came on again. I've contacted the dealership to schedule a time at the end of week or early Saturday to take the truck back again. While reviewing other complaints, I noticed a similar problem where the customer indicated the "Service Tow System" light was coming on. It too was allegedly caused from moisture intrusion. I'm currently over 3 hours from home through the end of the week. I'm hoping the truck will make it home without creating a catastrophe on the Interstate between here and there.

NHTSA ODI #11518758

Mileage unknown · Jan 30, 2023
EngineFuel/propulsion SystemPower TrainInjury

JULY 2022 DPF filter was throwing check engine light. Took to dealer to get diagnosed, part was ordered and the DPF was replaced August 19th 2022. Started to get headaches in vehicle while driving it. OCT 9th ended up in hospital after driving vehicle and was diagnosed with CARBON MONOXIDE POISONING. Experienced symptoms of losi…

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JULY 2022 DPF filter was throwing check engine light. Took to dealer to get diagnosed, part was ordered and the DPF was replaced August 19th 2022. Started to get headaches in vehicle while driving it. OCT 9th ended up in hospital after driving vehicle and was diagnosed with CARBON MONOXIDE POISONING. Experienced symptoms of losing consciousness, worst headache I've ever had, nausea for 5 hours, loss of feeling in body and seizing of body. Took truck to dealer to get inspected twice and nothing was found to be wrong with it. NOV 10th Took truck on another road trip and was having similar symptoms as before however had more chest pain this time so went back to hospital. Took truck back to dealer to have inspected again and was told that it was fine. Nov 18th took truck on another road trip and within 20 mins of driving had another horrible headache. Pulled over and needed to get air and ended up driving truck 4 hours home with windows and sunroof open to avoid getting carbon monoxide poisoning again. I have been ill since August and that is due to diesel and carbon monoxide poisoning every single time I drive the vehicle which is daily. The truck has been now at the dealership for 70 days without any update or improvement in the case.

NHTSA ODI #11504538

Mileage unknown · Mar 16, 2022
Power Train

DEF Tank Heater Vehicle goes into a limp mode after a defined mileage. Dealer confirmed the tank heater is bad. The part is on backorder with no known production date.

NHTSA ODI #11457019

Official recalls

6

24V797000 · Power Train:automatic Transmission:control Module:software; Power Train:automatic Transmission:fluid/lubricant:valves/valve Body

Oct 24, 2024

General Motors, LLC (GM) is recalling certain 2020-2022 Chevrolet Silverado 1500, 2500, 3500, GMC Sierra 1500, 2500, 3500, 2021 Cadillac Escalade, Escalade ESV, Chevrolet Tahoe, Suburban, GMC Yukon, and Yukon XL vehicles equipped with diesel engines. The transmission control valve may fail and cause the rear wheels to lock-up.

Consequence & remedy

Consequence: Rear wheel lock-up can increase the risk of a crash.

Remedy: Dealers will install new transmission control module software, free of charge. GM will provide a special coverage program to cover the repair of transmissions that are identified by the remedy software as containing a defective control valve. Owner notification letters were mailed December 12, 2024. Owners may contact GM customer service at 1-888-988-7267, Cadillac customer service at 1-800-458-8006, GMC customer service at GMC 1-800-462-8782 or Chevrolet customer service at 1-800-222-1020. GM's number for this recall is N242454440.

Additional source detail variants (2)

Power Train:automatic Transmission:fluid/lubricant:valves/valve Body

General Motors, LLC (GM) is recalling certain 2020-2022 Chevrolet Silverado 1500, 2500, 3500, GMC Sierra 1500, 2500, 3500, 2021 Cadillac Escalade, Escalade ESV, Chevrolet Tahoe, Suburban, GMC Yukon, and Yukon XL vehicles equipped with diesel engines. The transmission control valve may fail and cause the rear wheels to lock-up.

Consequence: Rear wheel lock-up can increase the risk of a crash.

Remedy: Dealers will install new transmission control module software, free of charge. GM will provide a special coverage program to cover the repair of transmissions that are identified by the remedy software as containing a defective control valve. Owner notification letters were mailed December 12, 2024. Owners may contact GM customer service at 1-888-988-7267, Cadillac customer service at 1-800-458-8006, GMC customer service at GMC 1-800-462-8782 or Chevrolet customer service at 1-800-222-1020. GM's number for this recall is N242454440.

Power Train:automatic Transmission:control Module:software

General Motors, LLC (GM) is recalling certain 2020-2022 Chevrolet Silverado 1500, 2500, 3500, GMC Sierra 1500, 2500, 3500, 2021 Cadillac Escalade, Escalade ESV, Chevrolet Tahoe, Suburban, GMC Yukon, and Yukon XL vehicles equipped with diesel engines. The transmission control valve may fail and cause the rear wheels to lock-up.

Consequence: Rear wheel lock-up can increase the risk of a crash.

Remedy: Dealers will install new transmission control module software, free of charge. GM will provide a special coverage program to cover the repair of transmissions that are identified by the remedy software as containing a defective control valve. Owner notification letters were mailed December 12, 2024. Owners may contact GM customer service at 1-888-988-7267, Cadillac customer service at 1-800-458-8006, GMC customer service at GMC 1-800-462-8782 or Chevrolet customer service at 1-800-222-1020. GM's number for this recall is N242454440.

24V060000 · Latches/locks/linkages:tailgate:latch

Feb 1, 2024

General Motors, LLC (GM) is recalling certain 2020-2024 Chevrolet Silverado 2500, 3500, GMC Sierra 2500 and 3500 vehicles equipped with power-unlatching tailgates. The tailgate's electronic gate-release switch may short circuit due to water intrusion, which can result in the tailgate inadvertently unlatching while the vehicle is in park.

Consequence & remedy

Consequence: An unlatched tailgate may open while driving and result in a loss of unsecured cargo, creating a road hazard and increasing the risk of a crash.

Remedy: Owners are advised to check that the tailgate is closed and latched before driving. Dealers will replace the exterior touchpad switch assemblies, free of charge. Owner notification letters were mailed May 17, 2024. Owners may contact Chevrolet customer service at 1-800-222-1020 or GMC customer service at 1-800-462-8782. GM's number for this recall is N232426400.

21V758000 · Service Brakes, Hydraulic:power Assist:electric:control Module

Sep 29, 2021

General Motors, LLC (GM) is recalling certain 2021-2022 Chevrolet Silverado 2500, Silverado 3500, GMC Sierra 2500, and Sierra 3500 vehicles with electronic brake control modules (EBCM) replaced during vehicle assembly. The bolts that attach the brake pressure modulator valve (BPMV) assembly may not be properly tightened, which could fail to seal the two sub-assemblies and allow water intrusion.

Consequence & remedy

Consequence: Water in the BPMV may cause an electrical short circuit and increase the risk of fire.

Remedy: Owners are advised to park outside and away from other structures until the recall repair is completed. Dealers will replace the BPMV assembly, free of charge. Owner notification letters were mailed on October 20, 2021. Owners may contact Chevrolet customer service at 1-800-222-1020 or GMC customer service at 1-800-462-8782. GM's number for this recall is N212349181.

21V578000 · Tires:temporary/emergency Spare Tire

Jul 29, 2021

General Motors, LLC. (GM) is recalling certain 2020-2021 Chevrolet Silverado 2500 and GMC Sierra 2500 vehicles equipped with a 17" spare tire (RPO ZHQ or ZXT) and either the 20" accessory road tire (RPO REM) or the 18" accessory road tire (RPO Q2V). Operating the spare tire with other 20" or 18" tires can prevent the Anti-Lock Braking System (ABS) from engaging.

Consequence & remedy

Consequence: An ABS system that cannot control the rear wheels independently increases the risk of a crash.

Remedy: Dealers will provide the appropriate spare tire and apply a new spare tire information label, free of charge. Owner notification letters were mailed on October 18, 2021. Owners may contact Chevrolet customer service at 1-800-222-1020; GMC customer service at 1-800-462-8782. GM's number for this recall is N212329780.

20V811000 · Seat Belts; Seat Belts:critical Fasteners

Dec 23, 2020

General Motors, LLC (GM) is recalling certain 2020 Chevrolet Bolt EV and 2021 GMC Canyon and Sierra 1500, 2500 and 3500, Yukon, Yukon XL, Cadillac Escalade and Escalade ESV and Chevrolet Blazer, Camaro, Colorado, Equinox, Silverado 1500, 2500 and 3500, Suburban and Tahoe vehicles. Incorrect bolts may have been used at one or more fastening locations to secure the seat belts to the vehicle. If an incorrect bolt was used, the seat belt may not be properly attached to the vehicle.

Consequence & remedy

Consequence: If a seat belt assembly is not properly attached to the vehicle, the seat belt may not properly restrain an occupant in the event of a crash, increasing the risk of injury.

Remedy: GM will notify owners, and dealers will replace the suspect bolts, free of charge. The recall began January 29, 2021. Owners may contact GMC customer service at 1-800-462-8785, Cadillac customer service at 1-800-458-8006, or Chevrolet customer service at 1-800-222-1020. GM's number for this recall is N202322230.

Additional source detail variants (2)

Seat Belts:critical Fasteners

General Motors, LLC (GM) is recalling certain 2020 Chevrolet Bolt EV and 2021 GMC Canyon and Sierra 1500, 2500 and 3500, Yukon, Yukon XL, Cadillac Escalade and Escalade ESV and Chevrolet Blazer, Camaro, Colorado, Equinox, Silverado 1500, 2500 and 3500, Suburban and Tahoe vehicles. Incorrect bolts may have been used at one or more fastening locations to secure the seat belts to the vehicle. If an incorrect bolt was used, the seat belt may not be properly attached to the vehicle.

Consequence: If a seat belt assembly is not properly attached to the vehicle, the seat belt may not properly restrain an occupant in the event of a crash, increasing the risk of injury.

Remedy: GM will notify owners, and dealers will replace the suspect bolts, free of charge. The recall began January 29, 2021. Owners may contact GMC customer service at 1-800-462-8785, Cadillac customer service at 1-800-458-8006, or Chevrolet customer service at 1-800-222-1020. GM's number for this recall is N202322230.

Seat Belts

General Motors, LLC (GM) is recalling certain 2020 Chevrolet Bolt EV and 2021 GMC Canyon and Sierra 1500, 2500 and 3500, Yukon, Yukon XL, Cadillac Escalade and Escalade ESV and Chevrolet Blazer, Camaro, Colorado, Equinox, Silverado 1500, 2500 and 3500, Suburban and Tahoe vehicles. Incorrect bolts may have been used at one or more fastening locations to secure the seat belts to the vehicle. If an incorrect bolt was used, the seat belt may not be properly attached to the vehicle.

Consequence: If a seat belt assembly is not properly attached to the vehicle, the seat belt may not properly restrain an occupant in the event of a crash, increasing the risk of injury.

Remedy: GM will notify owners, and dealers will replace the suspect bolts, free of charge. The recall began January 29, 2021. Owners may contact GMC customer service at 1-800-462-8785, Cadillac customer service at 1-800-458-8006, or Chevrolet customer service at 1-800-222-1020. GM's number for this recall is N202322230.

20V792000 · Seat Belts; Seat Belts:critical Fasteners

Dec 17, 2020

General Motors, LLC (GM) is recalling certain 2019-2021 Chevrolet Silverado 1500 and GMC Sierra 1500, 2021 Chevrolet Suburban and Tahoe and GMC Yukon XL and 2020-2021 Chevrolet Silverado 2500 and 3500 and GMC Sierra 2500 and 3500 vehicles. The seat belt brackets may not be secured to the seat frame in the front-row center seating position.

Consequence & remedy

Consequence: If a seat-belt bracket is not secured, the seat belt may not properly restrain an occupant in the front-row center seat position, increasing the risk of injury in a crash.

Remedy: GM will notify owners, and dealers will inspect left-side and right-side front-row center seat-belt bracket attachments and reassemble it correctly as necessary, free of charge. The recall began January 26, 2021. Owners may contact GMC customer service at 1-800-462-8782, Chevrolet customer service at 1-800-222-1020. GM's number for this recall is N202314670.

Additional source detail variants (2)

Seat Belts:critical Fasteners

General Motors, LLC (GM) is recalling certain 2019-2021 Chevrolet Silverado 1500 and GMC Sierra 1500, 2021 Chevrolet Suburban and Tahoe and GMC Yukon XL and 2020-2021 Chevrolet Silverado 2500 and 3500 and GMC Sierra 2500 and 3500 vehicles. The seat belt brackets may not be secured to the seat frame in the front-row center seating position.

Consequence: If a seat-belt bracket is not secured, the seat belt may not properly restrain an occupant in the front-row center seat position, increasing the risk of injury in a crash.

Remedy: GM will notify owners, and dealers will inspect left-side and right-side front-row center seat-belt bracket attachments and reassemble it correctly as necessary, free of charge. The recall began January 26, 2021. Owners may contact GMC customer service at 1-800-462-8782, Chevrolet customer service at 1-800-222-1020. GM's number for this recall is N202314670.

Seat Belts

General Motors, LLC (GM) is recalling certain 2019-2021 Chevrolet Silverado 1500 and GMC Sierra 1500, 2021 Chevrolet Suburban and Tahoe and GMC Yukon XL and 2020-2021 Chevrolet Silverado 2500 and 3500 and GMC Sierra 2500 and 3500 vehicles. The seat belt brackets may not be secured to the seat frame in the front-row center seating position.

Consequence: If a seat-belt bracket is not secured, the seat belt may not properly restrain an occupant in the front-row center seat position, increasing the risk of injury in a crash.

Remedy: GM will notify owners, and dealers will inspect left-side and right-side front-row center seat-belt bracket attachments and reassemble it correctly as necessary, free of charge. The recall began January 26, 2021. Owners may contact GMC customer service at 1-800-462-8782, Chevrolet customer service at 1-800-222-1020. GM's number for this recall is N202314670.

Model-level recall history does not show whether a particular VIN is affected or has received a repair. Check a VIN with NHTSA ↗

NHTSA investigations

1

PE21010 · Air Bag Malfunction

Opened Apr 9, 2021 · Closed Aug 24, 2023

Status: closed (inferred from source dates) · Air Bags; Air Bags:frontal; Air Bags:frontal:driver Side:inflator Module; Air Bags:srs Malfunction Warning Lamp/light

On April 9, 2021, the Office of Defects Investigations (ODI) opened PE21-010 to investigate instances of air bag malfunction indicator light (MIL) illumination and potential for frontal air bag non-deployment in several vehicles manufactured by General Motors (GM). The vehicles included model year (MY) 2020 through 2021 CT4 and CT5 passenger cars, Sierra and Silverado trucks (1500/2500/3500 models), XT4 and MY 2021 Escalade, Suburban, Tahoe, Yukon SUVs.Technical Service Bulletin (TSB) 21-NA-005, issued in March 2021, addresses air bag MIL illumination with diagnostic trouble codes (DTCs) B0001-1B or B0012-0D. It cites rust particles in the connection terminal interface of the driver air bag inflator housing as the cause of the air bag MIL illumination. Illumination of the air bag MIL under these circumstances may result in a non-deployment of the frontal driver air bag during a frontal collision and increased risk of injury to the driver.GM stated a correlation exists between production delays due to the pandemic shutdown and premature corrosion initiation on the surface of the air bag inflator housing, which, in some cases, caused rust development during a seven (7) month period of vehicle production. In the rare instance when a rust particle dislodges from the driver air bag inflator housing and enters the air bag connector prior to assembly, an intermittent resistance spike at the air bag connector may result. The condition generates excessive resistance in the air bag electrical system when the steering wheel horn cover is manipulated or the steering wheel is turned. This excessive resistance is momentary. A crash commanding air bag deployment would need to occur exactly when the momentary excessive resistance occurs. Thus, there is a very low likelihood the hazard will present a risk during a crash of sufficient severity to warrant a commanded deployment. This failure mechanism occurs early in life and results in an air bag MIL illumination that corresponds to a DTC warning the driver that the vehicle requires service. The vehicle's air bag remains functional while the MIL is illuminated, and the DTC is present.Once the connection of the driver air bag module to the clockspring is made at the plant, or at the dealership for service, there is no longer an opportunity for rust migration into the connection point. The connector is sealed and has gold terminals, eliminating the expectation of fretting corrosion. All subject vehicles passed standard corrosion validation testing for extensive corrosion with no issue of air bag non-deployment.There is a low rate of occurrence: 1.41 incidents per thousand vehicles (IPTV) for all related occurrences, and 0.04 IPTV for occurrences with a mention of visible rust and/or corrosion on the air bag inflator housing. The average occurrence mileage for the subject vehicles is approximately 2,100. Every occurrence related to the alleged defect experienced an air bag MIL illumination and there are no verified allegations of air bag non-deployment within all data sources.To date, there have been no reported fires, crashes, injuries, or fatalities related to this issue. In view of the low rate, and the nature of early-life failure, the high detectability of failures, and low potential hazard to drivers, this Preliminary Evaluation (PE) is closed. The closing of this investigation does not constitute a finding by NHTSA that a safety-related defect does not exist. The agency reserves the right to take additional action if warranted by new circumstances.Review the ODI reports cited above at nhtsa.gov under the following identification numbers: 11537927, 11528888, 11525020, 11521401, 11506057, 11493107, 11486767, 11441525, 11433146, 11425658, 11423440, 11385267, 11376429, 11373466, 11366995.

Additional source detail variants (4)

Air Bags:frontal:driver Side:inflator Module

On April 9, 2021, the Office of Defects Investigations (ODI) opened PE21-010 to investigate instances of air bag malfunction indicator light (MIL) illumination and potential for frontal air bag non-deployment in several vehicles manufactured by General Motors (GM). The vehicles included model year (MY) 2020 through 2021 CT4 and CT5 passenger cars, Sierra and Silverado trucks (1500/2500/3500 models), XT4 and MY 2021 Escalade, Suburban, Tahoe, Yukon SUVs.Technical Service Bulletin (TSB) 21-NA-005, issued in March 2021, addresses air bag MIL illumination with diagnostic trouble codes (DTCs) B0001-1B or B0012-0D. It cites rust particles in the connection terminal interface of the driver air bag inflator housing as the cause of the air bag MIL illumination. Illumination of the air bag MIL under these circumstances may result in a non-deployment of the frontal driver air bag during a frontal collision and increased risk of injury to the driver.GM stated a correlation exists between production delays due to the pandemic shutdown and premature corrosion initiation on the surface of the air bag inflator housing, which, in some cases, caused rust development during a seven (7) month period of vehicle production. In the rare instance when a rust particle dislodges from the driver air bag inflator housing and enters the air bag connector prior to assembly, an intermittent resistance spike at the air bag connector may result. The condition generates excessive resistance in the air bag electrical system when the steering wheel horn cover is manipulated or the steering wheel is turned. This excessive resistance is momentary. A crash commanding air bag deployment would need to occur exactly when the momentary excessive resistance occurs. Thus, there is a very low likelihood the hazard will present a risk during a crash of sufficient severity to warrant a commanded deployment. This failure mechanism occurs early in life and results in an air bag MIL illumination that corresponds to a DTC warning the driver that the vehicle requires service. The vehicle's air bag remains functional while the MIL is illuminated, and the DTC is present.Once the connection of the driver air bag module to the clockspring is made at the plant, or at the dealership for service, there is no longer an opportunity for rust migration into the connection point. The connector is sealed and has gold terminals, eliminating the expectation of fretting corrosion. All subject vehicles passed standard corrosion validation testing for extensive corrosion with no issue of air bag non-deployment.There is a low rate of occurrence: 1.41 incidents per thousand vehicles (IPTV) for all related occurrences, and 0.04 IPTV for occurrences with a mention of visible rust and/or corrosion on the air bag inflator housing. The average occurrence mileage for the subject vehicles is approximately 2,100. Every occurrence related to the alleged defect experienced an air bag MIL illumination and there are no verified allegations of air bag non-deployment within all data sources.To date, there have been no reported fires, crashes, injuries, or fatalities related to this issue. In view of the low rate, and the nature of early-life failure, the high detectability of failures, and low potential hazard to drivers, this Preliminary Evaluation (PE) is closed. The closing of this investigation does not constitute a finding by NHTSA that a safety-related defect does not exist. The agency reserves the right to take additional action if warranted by new circumstances.Review the ODI reports cited above at nhtsa.gov under the following identification numbers: 11537927, 11528888, 11525020, 11521401, 11506057, 11493107, 11486767, 11441525, 11433146, 11425658, 11423440, 11385267, 11376429, 11373466, 11366995.

Air Bags:frontal

On April 9, 2021, the Office of Defects Investigations (ODI) opened PE21-010 to investigate instances of air bag malfunction indicator light (MIL) illumination and potential for frontal air bag non-deployment in several vehicles manufactured by General Motors (GM). The vehicles included model year (MY) 2020 through 2021 CT4 and CT5 passenger cars, Sierra and Silverado trucks (1500/2500/3500 models), XT4 and MY 2021 Escalade, Suburban, Tahoe, Yukon SUVs.Technical Service Bulletin (TSB) 21-NA-005, issued in March 2021, addresses air bag MIL illumination with diagnostic trouble codes (DTCs) B0001-1B or B0012-0D. It cites rust particles in the connection terminal interface of the driver air bag inflator housing as the cause of the air bag MIL illumination. Illumination of the air bag MIL under these circumstances may result in a non-deployment of the frontal driver air bag during a frontal collision and increased risk of injury to the driver.GM stated a correlation exists between production delays due to the pandemic shutdown and premature corrosion initiation on the surface of the air bag inflator housing, which, in some cases, caused rust development during a seven (7) month period of vehicle production. In the rare instance when a rust particle dislodges from the driver air bag inflator housing and enters the air bag connector prior to assembly, an intermittent resistance spike at the air bag connector may result. The condition generates excessive resistance in the air bag electrical system when the steering wheel horn cover is manipulated or the steering wheel is turned. This excessive resistance is momentary. A crash commanding air bag deployment would need to occur exactly when the momentary excessive resistance occurs. Thus, there is a very low likelihood the hazard will present a risk during a crash of sufficient severity to warrant a commanded deployment. This failure mechanism occurs early in life and results in an air bag MIL illumination that corresponds to a DTC warning the driver that the vehicle requires service. The vehicle's air bag remains functional while the MIL is illuminated, and the DTC is present.Once the connection of the driver air bag module to the clockspring is made at the plant, or at the dealership for service, there is no longer an opportunity for rust migration into the connection point. The connector is sealed and has gold terminals, eliminating the expectation of fretting corrosion. All subject vehicles passed standard corrosion validation testing for extensive corrosion with no issue of air bag non-deployment.There is a low rate of occurrence: 1.41 incidents per thousand vehicles (IPTV) for all related occurrences, and 0.04 IPTV for occurrences with a mention of visible rust and/or corrosion on the air bag inflator housing. The average occurrence mileage for the subject vehicles is approximately 2,100. Every occurrence related to the alleged defect experienced an air bag MIL illumination and there are no verified allegations of air bag non-deployment within all data sources.To date, there have been no reported fires, crashes, injuries, or fatalities related to this issue. In view of the low rate, and the nature of early-life failure, the high detectability of failures, and low potential hazard to drivers, this Preliminary Evaluation (PE) is closed. The closing of this investigation does not constitute a finding by NHTSA that a safety-related defect does not exist. The agency reserves the right to take additional action if warranted by new circumstances.Review the ODI reports cited above at nhtsa.gov under the following identification numbers: 11537927, 11528888, 11525020, 11521401, 11506057, 11493107, 11486767, 11441525, 11433146, 11425658, 11423440, 11385267, 11376429, 11373466, 11366995.

Air Bags

On April 9, 2021, the Office of Defects Investigations (ODI) opened PE21-010 to investigate instances of air bag malfunction indicator light (MIL) illumination and potential for frontal air bag non-deployment in several vehicles manufactured by General Motors (GM). The vehicles included model year (MY) 2020 through 2021 CT4 and CT5 passenger cars, Sierra and Silverado trucks (1500/2500/3500 models), XT4 and MY 2021 Escalade, Suburban, Tahoe, Yukon SUVs.Technical Service Bulletin (TSB) 21-NA-005, issued in March 2021, addresses air bag MIL illumination with diagnostic trouble codes (DTCs) B0001-1B or B0012-0D. It cites rust particles in the connection terminal interface of the driver air bag inflator housing as the cause of the air bag MIL illumination. Illumination of the air bag MIL under these circumstances may result in a non-deployment of the frontal driver air bag during a frontal collision and increased risk of injury to the driver.GM stated a correlation exists between production delays due to the pandemic shutdown and premature corrosion initiation on the surface of the air bag inflator housing, which, in some cases, caused rust development during a seven (7) month period of vehicle production. In the rare instance when a rust particle dislodges from the driver air bag inflator housing and enters the air bag connector prior to assembly, an intermittent resistance spike at the air bag connector may result. The condition generates excessive resistance in the air bag electrical system when the steering wheel horn cover is manipulated or the steering wheel is turned. This excessive resistance is momentary. A crash commanding air bag deployment would need to occur exactly when the momentary excessive resistance occurs. Thus, there is a very low likelihood the hazard will present a risk during a crash of sufficient severity to warrant a commanded deployment. This failure mechanism occurs early in life and results in an air bag MIL illumination that corresponds to a DTC warning the driver that the vehicle requires service. The vehicle's air bag remains functional while the MIL is illuminated, and the DTC is present.Once the connection of the driver air bag module to the clockspring is made at the plant, or at the dealership for service, there is no longer an opportunity for rust migration into the connection point. The connector is sealed and has gold terminals, eliminating the expectation of fretting corrosion. All subject vehicles passed standard corrosion validation testing for extensive corrosion with no issue of air bag non-deployment.There is a low rate of occurrence: 1.41 incidents per thousand vehicles (IPTV) for all related occurrences, and 0.04 IPTV for occurrences with a mention of visible rust and/or corrosion on the air bag inflator housing. The average occurrence mileage for the subject vehicles is approximately 2,100. Every occurrence related to the alleged defect experienced an air bag MIL illumination and there are no verified allegations of air bag non-deployment within all data sources.To date, there have been no reported fires, crashes, injuries, or fatalities related to this issue. In view of the low rate, and the nature of early-life failure, the high detectability of failures, and low potential hazard to drivers, this Preliminary Evaluation (PE) is closed. The closing of this investigation does not constitute a finding by NHTSA that a safety-related defect does not exist. The agency reserves the right to take additional action if warranted by new circumstances.Review the ODI reports cited above at nhtsa.gov under the following identification numbers: 11537927, 11528888, 11525020, 11521401, 11506057, 11493107, 11486767, 11441525, 11433146, 11425658, 11423440, 11385267, 11376429, 11373466, 11366995.

Air Bags:srs Malfunction Warning Lamp/light

On April 9, 2021, the Office of Defects Investigations (ODI) opened PE21-010 to investigate instances of air bag malfunction indicator light (MIL) illumination and potential for frontal air bag non-deployment in several vehicles manufactured by General Motors (GM). The vehicles included model year (MY) 2020 through 2021 CT4 and CT5 passenger cars, Sierra and Silverado trucks (1500/2500/3500 models), XT4 and MY 2021 Escalade, Suburban, Tahoe, Yukon SUVs.Technical Service Bulletin (TSB) 21-NA-005, issued in March 2021, addresses air bag MIL illumination with diagnostic trouble codes (DTCs) B0001-1B or B0012-0D. It cites rust particles in the connection terminal interface of the driver air bag inflator housing as the cause of the air bag MIL illumination. Illumination of the air bag MIL under these circumstances may result in a non-deployment of the frontal driver air bag during a frontal collision and increased risk of injury to the driver.GM stated a correlation exists between production delays due to the pandemic shutdown and premature corrosion initiation on the surface of the air bag inflator housing, which, in some cases, caused rust development during a seven (7) month period of vehicle production. In the rare instance when a rust particle dislodges from the driver air bag inflator housing and enters the air bag connector prior to assembly, an intermittent resistance spike at the air bag connector may result. The condition generates excessive resistance in the air bag electrical system when the steering wheel horn cover is manipulated or the steering wheel is turned. This excessive resistance is momentary. A crash commanding air bag deployment would need to occur exactly when the momentary excessive resistance occurs. Thus, there is a very low likelihood the hazard will present a risk during a crash of sufficient severity to warrant a commanded deployment. This failure mechanism occurs early in life and results in an air bag MIL illumination that corresponds to a DTC warning the driver that the vehicle requires service. The vehicle's air bag remains functional while the MIL is illuminated, and the DTC is present.Once the connection of the driver air bag module to the clockspring is made at the plant, or at the dealership for service, there is no longer an opportunity for rust migration into the connection point. The connector is sealed and has gold terminals, eliminating the expectation of fretting corrosion. All subject vehicles passed standard corrosion validation testing for extensive corrosion with no issue of air bag non-deployment.There is a low rate of occurrence: 1.41 incidents per thousand vehicles (IPTV) for all related occurrences, and 0.04 IPTV for occurrences with a mention of visible rust and/or corrosion on the air bag inflator housing. The average occurrence mileage for the subject vehicles is approximately 2,100. Every occurrence related to the alleged defect experienced an air bag MIL illumination and there are no verified allegations of air bag non-deployment within all data sources.To date, there have been no reported fires, crashes, injuries, or fatalities related to this issue. In view of the low rate, and the nature of early-life failure, the high detectability of failures, and low potential hazard to drivers, this Preliminary Evaluation (PE) is closed. The closing of this investigation does not constitute a finding by NHTSA that a safety-related defect does not exist. The agency reserves the right to take additional action if warranted by new circumstances.Review the ODI reports cited above at nhtsa.gov under the following identification numbers: 11537927, 11528888, 11525020, 11521401, 11506057, 11493107, 11486767, 11441525, 11433146, 11425658, 11423440, 11385267, 11376429, 11373466, 11366995.