Safety Recall N222375270 Brake Pressure Switch Connector Fire – 2019-2023 Chevrolet Silverado Medium Duty 4500HD/5500HD/6500HD

SEOCONTENT-START

GLOBAL SAFETY FIELD INVESTIGATIONS DCS6532 URGENT – DISTRIBUTE IMMEDIATELY Date: April 13, 2023 Subject: Stop Delivery Order for Safety Recall N222375270 Brake Pressure Switch Connector Fire Models: 2019-2023 Chevrolet Silverado Medium Duty 4500HD/5500HD/6500HD Equipped with 6.6L Duramax Diesel Engine (RPO L5D) To: All General Motors Medium Duty Dealers STOP DELIVERY ORDER Effective immediately, stop the delivery of certain 2019-2023 model year Chevrolet Silverado Medium Duty 4500HD/5500HD/6500HD vehicles in new or used vehicle inventory. General Motors has notified the National Highway Traffic Safety Administration (NHTSA) about a safety recall that involves these vehicles. The GM recall number is N222375270. It is a violation of federal law for a dealer to deliver a new motor vehicle or any new or used item of motor vehicle equipment (including a tire) covered by this notification until the defect is remedied. These vehicles may have a brake pressure sensor assembly that allows brake fluid to leak beyond the diaphragm seal into the pressure switch. The brake fluid may seep into the sensor’s electrical components and short the brake pressure switch and the associated fuse. If brake fluid shorts the brake pressure switch and the associated fuse, the circuit can generate excessive heat that could result in a fire, increasing the risk of injury. An underhood fire may occur when the vehicle is off and possibly unattended. Until the recall remedy is performed, owners are advised to park their vehicles outdoors. This condition may declare with a “service brake system” malfunction indicator lamp. Parts are not currently available, but when parts are available, dealers will replace the master cylinder pressure sensor. Dealers will also inspect the associated wire harness and replace if necessary. Until further instructions are received, involved vehicles that are in dealers’ possession (new or used vehicle inventory, GM Certified Used, courtesy transportation vehicles, dealer shuttle vehicles, etc.) must be held and not delivered to customers, dealer-traded, released to auction, used for demonstration purposes or any other dealer use. All GM Certified Used vehicles currently in the dealers’ inventory within the Certified Pre-Owned Inventory System (CPOIS) will be de-certified. The Investigate Vehicle History (IVH) screen in the Global Warranty Management (GWM) system has been updated for this recall. This action has been taken to assist dealers with determining which vehicles are involved so they can properly respond to customer inquiries. A list of involved vehicles that have been identified as being in dealer new vehicle inventory is attached to this message. It is sorted by dealer Business Associate Code (BAC) for easy reference. Your dealership’s BAC will not be listed if none of the involved vehicles are currently in your new vehicle inventory. To identify involved vehicles in dealer used inventory, run an Open VIN Report or Field Action Initiation Report using Field Action Reports-GFAM within the Maxis Dealer Application in GlobalConnect. Frequently Asked Questions Document (FAQs) Attached to this message you will find a document that addresses the ten most likely questions customers may have regarding this Safety Recall. Please use this information as an aid to confidently answer customer concerns. Until the recall bulletin is released, the Investigate Vehicle History (IVH) screen in the Global Warranty Management (GWM) system will display “04/13/2023” under Release Date and “Incomplete – Remedy Not Available” under Status. This means the required repair is not yet available and dealers should not attempt to perform any repairs. We are working with the supplier to obtain the required parts as quickly as possible. When a sufficient quantity of parts are available, the recall bulletin will be released and dealers can begin repairing vehicles. END OF MESSAGE GLOBAL SAFETY FIELD INVESTIGATIONS

**************************************************************************************************************

OMB Control No.: 2127-0004 Part 573 Safety Recall Report 23V-266 The information contained in this report was submitted pursuant to 49 CFR §573 Manufacturer Name : General Motors, LLC Submission Date : APR 14, 2023 NHTSA Recall No. : 23V-266 Manufacturer Recall No. : N222375270 Manufacturer Information : Manufacturer Name : General Motors, LLC Address : 29427 Louis Chevrolet Road MAIL CODE 480-210-2V WARREN MI 48093 Company phone : 586-596-1733 Population : Number of potentially involved : 40,428 Estimated percentage with defect : 1 % Vehicle Information : Vehicle 1 : 2019-2023 Chevrolet 4500HD/5500HD/6500HD Vehicle Type : Body Style : Power Train : NR Descriptive Information : Manufacturing records were used to identify vehicles built within the affected build window. Vehicles prior to 2019 model year use a different design. Production Dates : MAY 23, 2018 – APR 05, 2023 VIN Range 1 : Begin : NR End : NR Not sequential Description of Defect : Description of the Defect : General Motors has decided that a defect which relates to motor vehicle safety may exist in certain 2019 – 2023 model year Chevrolet Silverado Medium Duty 4500HD/5500HD/6500HD vehicles. These vehicles may have a brake pressure sensor assembly that allows brake fluid to leak beyond the diaphragm seal into the pressure switch. The brake fluid may seep into the sensor’s electrical components and short the brake pressure switch and the associated fuse. FMVSS 1 : NR FMVSS 2 : NR Description of the Safety Risk : If brake fluid shorts the brake pressure switch and the associated fuse, the circuit can generate excessive heat that could result in a fire, increasing the risk of injury. An underhood fire may occur when the vehicle is off and possibly unattended. Description of the Cause : A zinc nickel plating and sealant used to inhibit corrosion within the pressure Part 573 Safety Recall Report 23V-266 Page 2 The information contained in this report was submitted pursuant to 49 CFR §573 sensor assembly may cause delamination of the sealant which results in small fragments of sealer underneath the diaphragm during assembly which allows brake fluid to slowly seep past the seal. Identification of Any Warning that can Occur : Until the recall remedy is performed, owners are advised to park their vehicles outdoors. This condition may declare with a “service brake system” malfunction indicator lamp. Involved Components : Component Name 1 : SWITCH, BRK PRESS WRNG (W/O TEE CONNECTOR) Component Description : Brake master cylinder pressure sensor Component Part Number : 19407495 Supplier Identification : Component Manufacturer Name : Navistar, Inc. Address : 2701 Navistar Dr. Lisle Illinois 60532 Country : United States Chronology : On August 9, 2022, GM opened a product investigation following a claim of a vehicle fire on a 2019 Chevrolet Silverado Medium Duty vehicle. As part of that investigation, GM coordinated with Navistar, the manufacturer of the subject vehicles, to review field data and warranty returned brake pressure sensors. While a series of tests failed to duplicate the SUFS vehicle’s condition, on January 25, 2023, a warranty returned sensor and harness was identified which exhibited signs of heat damage. This part was subjected to more detailed analysis, including X-ray scans which were completed on February 13, 2023, followed by chemistry laboratory analysis which was completed on February 28, 2023. The results from these analyses revealed the presence of brake fluid past the diaphragm seal, into the brake pressure switch and through the actual wire harness into the pump’s fuse circuit. Analysis of the returned components also revealed delamination of the corrosion inhibiting sealant, which allowed slow seepage of the brake fluid past the diaphragm seal. On March 30, 2023, Navistar reported one potentially related field incident involving a part with alleged heat damage. On April 5, 2023, Navistar provided GM a list of potentially affected vehicle VINs. Part 573 Safety Recall Report 23V-266 Page 3 The information contained in this report was submitted pursuant to 49 CFR §573 On April 6, 2023, GM’s Safety Field Action Decision Authority (SFADA) decided to conduct a safety recall. GM’s final analysis of the field data, including legal claims, identified a total of twenty-one potentially related complaints, eleven of which alleged a fire, smoke, or flame. GM was provided notice of those events between July 26, 2021, and January 25, 2023. GM is not aware of any accidents or injuries associated with this condition. Description of Remedy : Description of Remedy Program : Dealers will replace the master cylinder pressure sensor. Dealers will also inspect the associated wire harness and replace if necessary. Pursuant to 577.11, GM will provide reimbursement to owners for repairs according to the plan submitted on May 12, 2021. How Remedy Component Differs from Recalled Component : Replacement pressure sensor assemblies do not incorporate the corrosion inhibitor sealant that was delaminating and causing small fragments of sealer underneath of the diaphragm seal. Identify How/When Recall Condition was Corrected in Production : On March 21, 2023, Navistar began manufacturing with pressure sensor assemblies that do not incorporate the corrosion inhibitor sealant that was delaminating and causing small fragments of sealer underneath of the diaphragm seal. Recall Schedule : Description of Recall Schedule : Dealers will be notified on April 13, 2023. GM estimates interim owner notification will begin on May 29, 2023. GM will provide an estimate for owner notification of an available remedy when an estimate is available. Planned Dealer Notification Date : APR 13, 2023 – APR 13, 2023 Planned Owner Notification Date : MAY 29, 2023 – MAY 29, 2023 * NR – Not Reported

**************************************************************************************************************

OMB Control No.: 2127-0004 Part 573 Safety Recall Report 23V-266 The information contained in this report was submitted pursuant to 49 CFR §573 Manufacturer Name : General Motors, LLC Submission Date : APR 13, 2023 NHTSA Recall No. : 23V-266 Manufacturer Recall No. : N222375270 Manufacturer Information : Manufacturer Name : General Motors, LLC Address : 29427 Louis Chevrolet Road MAIL CODE 480-210-2V WARREN MI 48093 Company phone : 586-596-1733 Population : Number of potentially involved : 40,428 Estimated percentage with defect : 1 % Vehicle Information : Vehicle 1 : 2019-2023 Chevrolet 4500HD/5500HD/6500HD Vehicle Type : Body Style : Power Train : NR Descriptive Information : Manufacturing records were used to identify vehicles built within the affected build window. Vehicles prior to 2019 model year use a different design. Production Dates : MAY 23, 2018 – APR 05, 2023 VIN Range 1 : Begin : NR End : NR Not sequential Description of Defect : Description of the Defect : General Motors has decided that a defect which relates to motor vehicle safety may exist in certain 2019 – 2023 model year Chevrolet Silverado Medium Duty 4500HD/5500HD/6500HD vehicles. These vehicles may have a brake pressure sensor assembly that allows brake fluid to leak beyond the diaphragm seal into the pressure switch. The brake fluid may seep into the sensor’s electrical components and short the brake pressure switch and the associated fuse. FMVSS 1 : NR FMVSS 2 : NR Description of the Safety Risk : If brake fluid shorts the brake pressure switch and the associated fuse, the circuit can generate excessive heat that could result in a fire, increasing the risk of injury. An underhood fire may occur when the vehicle is off and possibly unattended. Description of the Cause : A zinc nickel plating and sealant used to inhibit corrosion within the pressure Part 573 Safety Recall Report 23V-266 Page 2 The information contained in this report was submitted pursuant to 49 CFR §573 sensor assembly may cause delamination of the sealant which results in small fragments of sealer underneath the diaphragm during assembly which allows brake fluid to slowly seep past the seal. Identification of Any Warning that can Occur : Until the recall remedy is performed, owners are advised to park their vehicles outdoors. This condition may declare with a “service brake system” malfunction indicator lamp. Involved Components : Component Name 1 : SWITCH, BRK PRESS WRNG (W/O TEE CONNECTOR) Component Description : Brake master cylinder pressure sensor Component Part Number : 19407495 Supplier Identification : Component Manufacturer Name : Navistar, Inc. Address : 6125 Urbana Road Springfield Ohio 45502 Country : United States Chronology : On August 9, 2022, GM opened a product investigation following a claim of a vehicle fire on a 2019 Chevrolet Silverado Medium Duty vehicle. As part of that investigation, GM coordinated with Navistar, the manufacturer of the subject vehicles, to review field data and warranty returned brake pressure sensors. While a series of tests failed to duplicate the SUFS vehicle’s condition, on January 25, 2023, a warranty returned sensor and harness was identified which exhibited signs of heat damage. This part was subjected to more detailed analysis, including X-ray scans which were completed on February 13, 2023, followed by chemistry laboratory analysis which was completed on February 28, 2023. The results from these analyses revealed the presence of brake fluid past the diaphragm seal, into the brake pressure switch and through the actual wire harness into the pump’s fuse circuit. Analysis of the returned components also revealed delamination of the corrosion inhibiting sealant, which allowed slow seepage of the brake fluid past the diaphragm seal. On March 30, 2023, Navistar reported one potentially related field incident involving a part with alleged heat damage. On April 5, 2023, Navistar provided GM a list of potentially affected vehicle VINs. Part 573 Safety Recall Report 23V-266 Page 3 The information contained in this report was submitted pursuant to 49 CFR §573 On April 6, 2023, GM’s Safety Field Action Decision Authority (SFADA) decided to conduct a safety recall. GM’s final analysis of the field data, including legal claims, identified a total of twenty-one potentially related complaints, eleven of which alleged a fire, smoke, or flame. GM was provided notice of those events between July 26, 2021, and January 25, 2023. GM is not aware of any accidents or injuries associated with this condition. Description of Remedy : Description of Remedy Program : Dealers will replace the master cylinder pressure sensor. Dealers will also inspect the associated wire harness and replace if necessary. Pursuant to 577.11, GM will provide reimbursement to owners for repairs according to the plan submitted on May 12, 2021. How Remedy Component Differs from Recalled Component : Replacement pressure sensor assemblies do not incorporate the corrosion inhibitor sealant that was delaminating and causing small fragments of sealer underneath of the diaphragm seal. Identify How/When Recall Condition was Corrected in Production : On March 21, 2023, Navistar began manufacturing with pressure sensor assemblies that do not incorporate the corrosion inhibitor sealant that was delaminating and causing small fragments of sealer underneath of the diaphragm seal. Recall Schedule : Description of Recall Schedule : Dealers will be notified on April 13, 2023. GM estimates interim owner notification will begin on May 29, 2023. GM will provide an estimate for owner notification of an available remedy when an estimate is available. Planned Dealer Notification Date : APR 13, 2023 – APR 13, 2023 Planned Owner Notification Date : MAY 29, 2023 – MAY 29, 2023 * NR – Not Reported

**************************************************************************************************************

**************************************************************************************************************

SEOCONTENT-END