Loss of Engine Power from Electrical Corrosion – 2023-2024 Chevrolet 3500HG, 4500HG, 2024 5500HG, 5500XG LFC

SEOCONTENT-START

OMB Control No.: 2127-0004 Part 573 Safety Recall Report 23V-564 The information contained in this report was submitted pursuant to 49 CFR §573 Manufacturer Name : Isuzu Motors Limited Submission Date : AUG 10, 2023 NHTSA Recall No. : 23V-564 Manufacturer Recall No. : V2305 Manufacturer Information : Manufacturer Name : Isuzu Motors Limited Address : 46401 Commerce Center Drive Plymouth MI 48170-2473 Company phone : 866-441-9638 Population : Number of potentially involved : 19,479 Estimated percentage with defect : 100 % Vehicle Information : Vehicle 1 : 2023-2024 ISUZU NPR Gas Vehicle Type : BUSES, MEDIUM & HEAVY VEHICLES Body Style : OTHER Power Train : GAS Descriptive Information : Recall population determined by production and sales records. It includes all production vehicles of these model years, makes, and models between the manufacturing dates provided. [1,208] Production Dates : APR 12, 2022 – JUL 10, 2023 VIN Range 1 : Begin : 54DB4W1D4PS200018 End : 54DB4W1D1RS207589 ✔ Not sequential Vehicle 2 : 2023-2024 ISUZU NPR HD Gas Vehicle Type : BUSES, MEDIUM & HEAVY VEHICLES Body Style : OTHER Power Train : GAS Descriptive Information : Recall population determined by production and sales records. It includes all production vehicles of these model years, makes, and models between the manufacturing dates provided. [11,788] Production Dates : APR 11, 2022 – JUL 12, 2023 VIN Range 1 : Begin : 54DC4J1D9PS200006 End : 54DC4W1D2RS207718 ✔ Not sequential Part 573 Safety Recall Report 23V-564 Page 2 The information contained in this report was submitted pursuant to 49 CFR §573 Vehicle 3 : 2024-2024 ISUZU NQR Gas Vehicle Type : BUSES, MEDIUM & HEAVY VEHICLES Body Style : OTHER Power Train : GAS Descriptive Information : Recall population determined by production and sales records. It includes all production vehicles of these model years, makes, and models between the manufacturing dates provided. [146] Production Dates : APR 05, 2023 – JUL 09, 2023 VIN Range 1 : Begin : 54DE5W1D3RS500002 End : 54DE5W1D6RS500205 ✔ Not sequential Vehicle 4 : 2024-2024 ISUZU NRR Gas Vehicle Type : BUSES, MEDIUM & HEAVY VEHICLES Body Style : OTHER Power Train : GAS Descriptive Information : Recall population determined by production and sales records. It includes all production vehicles of these model years, makes, and models between the manufacturing dates provided. [921] Production Dates : APR 06, 2023 – JUL 10, 2023 VIN Range 1 : Begin : 54DE5W1DXRSR00008 End : 54DE5W1D8RSR01173 ✔ Not sequential Vehicle 5 : 2023-2024 CHEVROLET LCF 3500HG Vehicle Type : BUSES, MEDIUM & HEAVY VEHICLES Body Style : OTHER Power Train : GAS Descriptive Information : Recall population determined by production and sales records. It includes all production vehicles of these model years, makes, and models between the manufacturing dates provided. [662] Production Dates : APR 12, 2022 – JUL 07, 2023 VIN Range 1 : Begin : 54DBDW1D1PS200042 End : 54DBDW1D7RS207421 ✔ Not sequential Vehicle 6 : 2023-2024 CHEVROLET LCF 4500HG Vehicle Type : BUSES, MEDIUM & HEAVY VEHICLES Body Style : OTHER Power Train : GAS Descriptive Information : Recall population determined by production and sales records. It includes all production vehicles of these model years, makes, and models between the manufacturing dates provided. [4,692] Production Dates : APR 11, 2022 – JUL 12, 2023 VIN Range 1 : Begin : 54DCDJ1D4PS200012 End : 54DCDW1D5RS207745 ✔ Not sequential Part 573 Safety Recall Report 23V-564 Page 3 The information contained in this report was submitted pursuant to 49 CFR §573 Vehicle 7 : 2024-2024 CHEVROLET LCF 5500HG Vehicle Type : BUSES, MEDIUM & HEAVY VEHICLES Body Style : OTHER Power Train : GAS Descriptive Information : Recall population determined by production and sales records. It includes all production vehicles of these model years, makes, and models between the manufacturing dates provided. [18] Production Dates : JUN 02, 2023 – JUN 07, 2023 VIN Range 1 : Begin : 54DEEJ1D3RS500147 End : 54DEEJ1D5RS500151 ✔ Not sequential Vehicle 8 : 2024-2024 CHEVROLET LCF 5500XG Vehicle Type : BUSES, MEDIUM & HEAVY VEHICLES Body Style : OTHER Power Train : GAS Descriptive Information : Recall population determined by production and sales records. It includes all production vehicles of these model years, makes, and models between the manufacturing dates provided. [44] Production Dates : JUN 02, 2023 – JUL 08, 2023 VIN Range 1 : Begin : 54DEEW1D0RSR00549 End : 54DEEJ1D9RSR01159 ✔ Not sequential Description of Defect : Description of the Defect : When the chassis harnesses of the subject vehicles were designed, an incorrectly sized wire seal was selected for the 2 externally mounted engine ignition coil pack fuse holders. This results in the potential for water intrusion into the fuse holders and eventual corrosion or failure of the fuses. FMVSS 1 : NR FMVSS 2 : NR Description of the Safety Risk : If the ignition coil pack fuses corrode or fail, one or more of the following events could occur – in each case, increasing the risk of a crash: • Engine will begin to misfire and power output may be reduced, resulting in slower than normal vehicle acceleration (roughly 30% increased acceleration times); • Engine will derate and maximum vehicle speed will be limited to 5 MPH (power brake assist and power steering assist will still function normally); • While trying to start the engine, it may stall and not restart. Description of the Cause : There was a subcomponent specification error in the engineering drawing for the chassis harness which improperly called out for the use of a silicone wire seal with two large 2.45mm openings for the wires instead of one 2.45mm and one 1.55mm opening. Part 573 Safety Recall Report 23V-564 Page 4 The information contained in this report was submitted pursuant to 49 CFR §573 Identification of Any Warning that can Occur : • A steady Check Engine MIL with an audible engine misfire and vehicle shake or vibration may occur. • The vehicle will also have reduced power and may emit a fuel smell from the exhaust. • Continued use in this condition will result in a continuous flashing Check Engine MIL and a vehicle speed derate to 5MPH. If this occurs, power steering assist and power brake assist functions are still retained. Involved Components : Component Name 1 : Main Chassis Harness Component Description : Harness, Chassis Component Part Number : 8977986391, 8978736183, 8977986401, 8978736193, 8977986411, 8978736203, 8977986421, 8978736213, 8978 Supplier Identification : Component Manufacturer Name : American Furukawa INC Address : 2181 International St. Columbus Ohio 43228 Country : United States Chronology : Chronology uploaded separately. Part 573 Safety Recall Report 23V-564 Page 5 The information contained in this report was submitted pursuant to 49 CFR §573 Description of Remedy : Description of Remedy Program : For vehicles that have not yet been delivered to the first retail purchaser, dealers will apply a silicone sealant to the rear of the existing fuse holders or install revised coil pack fuse holders (“pigtails”) depending on vehicle class and body upfit status. For vehicles delivered into customer hands, dealers will replace both engine ignition coil pack fuse holder assemblies with the revised coil pack fuse holders (“pigtails”). REIMBURSEMENT: All vehicles that previously had this condition repaired would have been covered under the New Truck Warranty or Engine Emission Warranty standard on all new purchases. How Remedy Component Differs from Recalled Component : The Ignition coil pack circuits in future chassis harnesses will be assembled with two 2.9mm diameter wires instead of one 2.1mm and one 2.9mm diameter wire, this will result in a correct wire to seal interference and prevent water intrusion into the fuse holder. Identify How/When Recall Condition was Corrected in Production : Vehicles produced on or after July 12, 2023 have silicone applied to the rear of the fuse holders to prevent water intrusion. A revised harness is planned for future production which will utilize two 2.9mm diameter wires for each fuse holder. Recall Schedule : Description of Recall Schedule : Isuzu and Chevrolet will notify their respective vehicle owners and dealers of this recall. They will be informed that the recall repairs will be done free of charge. However, remedy parts for customer vehicles are not currently available and Isuzu does not yet know when the parts will become available. Therefore, it will be necessary to send an Interim Owner Letter advising vehicle owners of the recall, that remedy parts are not currently available and that they will receive a second letter when remedy parts become available. The interim recall owner notification is expected to begin 9/29/2023. In addition, it is anticipated that remedy parts for affected vehicles in dealer inventory will not be available for approximately six weeks. As a result, the Stop Sale Notice that will be provided to dealers upon submission of this Defect Information Report will instruct dealers to hold affected vehicles in their inventory until receiving further notification and a Campaign Bulletin when remedy parts become available. For additional information, Isuzu owners may contact Isuzu Customer Relations at 1-866-441-9638 and Chevrolet owners may contact the GM Medium Duty Truck assistance line at 1-800-862-4389. Planned Dealer Notification Date : AUG 11, 2023 – AUG 11, 2023 Planned Owner Notification Date : SEP 29, 2023 – SEP 29, 2023 Part 573 Safety Recall Report 23V-564 Page 6 The information contained in this report was submitted pursuant to 49 CFR §573 * NR – Not Reported

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

Reference Number: GCUS-3-3002 Stop Delivery Order for Safety Recall N232419340 – Ignition Coil Pack Fuse GLOBAL SAFETY FIELD INVESTIGATIONS DCS6647 URGENT – DISTRIBUTE IMMEDIATELY Date: August 10, 2023 Subject: Stop Delivery Order for Safety Recall N232419340 Ignition Coil Pack Fuse Models: 2023 Chevrolet 3500/4500 Low Cab Forward 2024 Chevrolet 3500 HG/4500 HG Low Cab Forward 2024 Chevrolet 5500 HG/5500 XG Low Cab Forward Equipped with 6.6L Gasoline Engine (RPO L8T) To: All General Motors Dealers STOP DELIVERY ORDER Effective immediately, stop the delivery of certain 2023 and 2024 model year Chevrolet Low Cab Forward vehicles in new or used vehicle inventory. Isuzu Motors Limited has notified the National Highway Traffic Safety Administration (NHTSA) about a safety recall that involves these vehicles. The GM recall number is N232419340. 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. Isuzu Motors Limited, the manufacturer of these vehicles, has determined a defect, which relates to motor vehicle safety, exists in certain 2023 and 2024 model year Chevrolet Low Cab Forward vehicles equipped with 6.6L (L8T) gasoline engines. In the affected vehicles, an incorrectly sized wire seal was selected for the 2 externally mounted engine ignition coil pack fuse holders. This results in the potential for water intrusion into the fuse holders and eventual corrosion or failure of the fuses. If the ignition coil pack fuses corrode or fail, one or more of the following events may occur, in each case increasing the risk of a crash: (1) the Check Engine Malfunction Indicator Light (MIL) may illuminate and the engine may misfire and result in reduced power output and slower than normal acceleration; (2) the vehicle may derate and limit maximum vehicle speed to 5 MPH (power steering and power brake assist will still function normally); and (3) if you shut off the engine, it may stall when you try to start it and not restart. Parts are not currently available, but when parts are available, dealers are to apply a silicone sealant to the rear of the existing fuse holder plug. 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 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 “8/10/2023” 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

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

Reference Number: GCUS-3-3015 N232419340 – Safety Recall – Ignition Coil Pack Fuse – Application for Used Vehicle Working Capital GM CUSTOMER CARE AND AFTERSALES DCS6659 URGENT – DISTRIBUTE IMMEDIATELY Date: August 25, 2023 Subject: N232419340 – Safety Recall Ignition Coil Pack Fuse Application for Used Vehicle Working Capital Assistance Program (WCAP) Models: 2023 Chevrolet 3500/4500 Low Cab Forward 2024 Chevrolet 3500 HG/4500 HG Low Cab Forward 2024 Chevrolet 5500 HG/5500 XG Low Cab Forward Equipped with 6.6L Gasoline Engine (RPO L8T) To: All General Motors Dealers On August 10, 2023, GM sent to all GM dealers GlobalConnect Message GCUS-3-3002 regarding safety recall N232419340. The required repair to complete this recall is not yet available. Until further instructions are received, the 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 cannot be delivered to customers, dealer-traded, released to auction, used for demonstration purposes or put to any other use. This message is to inform dealers who have involved vehicles in their inventory that they can now apply for the used vehicle Working Capital Assistance Program (“WCAP”) for safety recall N232419340. Before proceeding with the application process described below, dealers must verify vehicle eligibility based on the program terms and guidelines that were provided in GM GlobalConnect Message GCUS-9-14456 dated March 29, 2023. Applications submitted on ineligible vehicles are subject to chargeback of any incentives paid to the dealer under the WCAP. Because compensation and tracking requires visibility into dealers’ inventory, dealers must also have agreed to a Dealer Data Share agreement with GM in order to receive any compensation under this program. To apply for the WCAP for safety recall N232419340, dealers must access the GM Global Warranty Management (GWM) system and submit a “ZSET” warranty transaction using the labor code provided below for each eligible vehicle. This zero dollar special transaction type is the dealer’s application for compensation and constitutes a representation from the dealer that the vehicle is eligible for WCAP assistance. Note: Acceptance of the warranty transaction does not ensure vehicle eligibility or guarantee the provision of any assistance as defined by program terms and guidelines. Labor Code Description Labor Time Trans Code 9800111 Working Capital Assistance for Safety Recall N232419340 N/A ZSET To be eligible for the WCAP, a vehicle must be in dealer inventory at the time the related field action bulletin is released. If a vehicle has been delivered, wholesaled or otherwise disposed of prior to release of the bulletin, the vehicle is not eligible for assistance. Additionally, recalled vehicles taken in on trade may be eligible for assistance if the dealer immediately reports the vehicle in used vehicle inventory via its Dealer Management System (DMS) and makes application through the GWM system. To ensure that GM is receiving daily inventory information, which is necessary to process payments and make eligibility determinations under the WCAP, the dealer’s vehicles must be properly identified in the dealership’s DMS. A daily feed of this information is provided to GM through the Dealer Data Share (DDS) agreement. Beginning with the 1st quarter of 2019, all WCAP payments will be facilitated through the Global Warranty Management (GWM) system. For each eligible vehicle, a qualifying dealer will submit for WCAP vehicle enrollment with a “ZSET” transaction type and for reimbursement with a “ZFAT” transaction type both through the GWM system. If approved, a WCAP credit for that vehicle will be issued through the GWM system similar to any other warranty credit. WCAP submission instructions and the required labor code will also be provided in the appropriate field action bulletin. Each WCAP transaction being credited will be clearly identified on the dealer’s daily credit memo. In order to receive payment, a dealer must have timely reported the vehicle in used vehicle inventory, retained the vehicle until the related field action bulletin is released, and properly applied for the WCAP payment. The vehicle must also be otherwise eligible under WCAP rules and guidelines. GM reserves the right to amend, modify, terminate, or cancel this program at any time in its sole discretion. END OF MESSAGE GM CUSTOMER CARE AND AFTERSALES

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

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

SEOCONTENT-END