Complaints over time
Complaints about the 2023 Mack MD by year filed
Owner complaints about this model year, by the year they were filed with NHTSA.
Source: NHTSA ODI complaints file. The lighter column runs through October.
Model year
2023 Mack MD
Truck, diesel, 4x2, built in United States. Owner complaints on file from Jun 17, 2026 to Jun 17, 2026.
Recall campaigns covering this model year216k vehicles or units across those campaigns
Owner complaints1Close to the median 2023 truck
Severity index0.02023 trucks average 0.0
First 24 months0Complaints in its first two years
Components
100% of complaints about the 2023 Mack MD name engine and cooling
Owner complaints by component. Hover or focus a bar for the crash, fire, injury or death count.
Source: NHTSA ODI complaints file. A complaint can name more than one component; it is counted under the first.
Recalls
2 recall campaigns cover the 2023 Mack MD
Check a specific vehicle by VIN on NHTSA's site: a campaign may cover only part of a model year's production.
| Campaign | Filed | Subject | Component | Vehicles | Remedy |
|---|---|---|---|---|---|
| 25V-666 | Oct 6, 2025 | Seat belt anchorage bracket may be improperly welded | Seat belts | 15,841 | Repair or modification |
| 22V-606 | Aug 9, 2022 | Engine control module (ECM) may experience an internal short-circuit, which can result in an unexpected engine shut down | Engine and cooling | 150 | Part replacement |
Source: NHTSA ODI recalls file.
Owner complaints
What owners reported about the 2023 Mack MD
The full text of every complaint filed with NHTSA about this model year, newest first. Complaints are filed by owners and are not verified by NHTSA; NHTSA removes personal details before publishing.
1 complaint on file, page 1 of 1.
- Filed Jun 17, 2026Failure Feb 26, 2025Monterey Park, CAEngine, Fuel/propulsion system, Power train
COMPONENTS THAT FAILED: Multiple systems failed in a connected chain. (1) The DPF aftertreatment differential pressure sensor — a CONFIRMED manufacturing defect per Cummins recall T7186/T7187 (Jan 2026). (2) The Allison automatic transmission — catastrophic internal failure: torque converter destroyed, flexplate warped and cracked, metal fragments throughout. (3) The transmission control unit wiring (circuits 143/123) reversed at the factory. The DEF sensor in the same aftertreatment system also failed back in Dec 2023, 14 months before the DPF symptoms — proving a system-wide defect. All failed components and repair invoices are available for inspection upon request. SAFETY RISK: After the dealer declared repairs complete, the truck was driven under 10 miles when the engine entered SEVERE DERATE (limp) mode WITHOUT WARNING, with four alerts firing at once including aftertreatment and transmission failures. Sudden, drastic power loss on a heavy commercial truck in live traffic is extremely dangerous — it can leave the vehicle unable to maintain highway speed, risking a collision with surrounding vehicles. The dealer released the truck in this hazardous state with no warning. CONFIRMED BY MULTIPLE SHOPS: Yes. The problem was reproduced and confirmed repeatedly — by the authorized dealer, by an independent transmission shop, and at final repair. The fault returned within 30 minutes on one visit and within 10 miles on another. INSPECTED BY: The authorized dealer and an independent service center inspected the vehicle and failed components. Documentation is available. WARNING SIGNS: Yes. Warning lamps appeared from the very first visit in Feb 2025 — transmission code P071A and high soot codes 1981/1922. They persisted for NINE MONTHS without proper repair, until the transmission catastrophically failed in Nov 2025. The vehicle was out of service over 45 days.
NHTSA complaint 11744905
Source: NHTSA ODI complaints file.
Investigations
NHTSA has not opened an investigation on this model year
Source: NHTSA ODI investigations file.
Service bulletins
69 manufacturer communications cover this model year
Technical service bulletins and other notices the manufacturer sent to dealers. A bulletin is not a recall; the 60 most recent are listed.
- CBR 2573-1 202604 Apr 9, 2026 · Service Bulletin/Repair Instructions
CBR - Mack Chassis - Through Shaft Bearing Retainer Breakage On Mack Carriers. - CBR 2362-3 202604 Apr 9, 2026 · Service Bulletin/Repair Instructions
CBR - Mack Carrier Nut Adhesive Change. - TSB M-432-002A 032026 Mar 12, 2026 · Service Bulletin/Repair Instructions
TSB - Cable, Gear Selector, Replacement - CBR 2712-7 032026 Mar 19, 2026 · Service Bulletin/Repair Instructions
CBR - No Start Condition After Over the Air Programing. - CBR 2107-22 202601 Jan 7, 2026 · Service Bulletin/Repair Instructions
CBR - Mack DEF Level (UQLS) Sensor Troubleshooting Guide - US17+OBD16 Emissions to US22+OBD2023 (DOES NOT APPLY TO AN(4) and PR(4)). - CBR 2172-5 082025 Aug 22, 2025 · Service Bulletin/Repair Instructions
CBR - When an OTA (Over-The-Air) job starts to program the VECU blocks the starter relay out, if the job ends in a Critical failure, the vehicle will remain in Safe State. - CBR 407 072025 Jul 17, 2025 · Service Bulletin/Repair Instructions
CBR - To correct the MID136 SID 66 FMI 7 fault code the latest Bendix VCP file will need to downloaded. - CBR 2488 072025 Jul 28, 2025 · Service Bulletin/Repair Instructions
CBR - A significant GPS reporting issue is affecting fleet operations, with trucks maintaining back-office communication but failing to transmit GPS location data. - CBR 2107-21 202505 May 27, 2025 · Service Bulletin/Repair Instructions
Mack DEF Level (UQLS) Sensor Troubleshooting Guide - US17+OBD16 Emissions and Newer - CBR-561 202503 Mar 6, 2025 · Service Bulletin/Repair Instructions
If oil dilution is suspected refer to the applicable CBR solution below: ∙ CBR-659Mack Chassis - Oil Diluted With Fuel; Fuel In Oil, Diagnostic Information - All Emissions, All Model Years - CBR-2016 202412 Dec 3, 2024 · Service Bulletin/Repair Instructions
Frame lean can be caused by several seemingly isolated possibilities. The two most common are suspension and frame assembly issues. - CBR-997 202411 Nov 14, 2024 · Service Bulletin/Repair Instructions
Vehicles may present with oil leak coming from the clutch/flywheel housing and observation of burned clutch smell or clutch slipping. These symptoms can be mistaken as a crankshaft rear main seal leak, when the actual cause is the crankshaft adaptor O-ring. - CBR-407 202409 Sep 13, 2024 · Service Bulletin/Repair Instructions
CBR: To correct the MID136 SID 66 FMI 7 fault code the latest Bendix VCP fi le will need to be downloaded. - CBR-2350 202407 Jul 2, 2024 · Service Bulletin/Repair Instructions
CBR: Telematics Gateway (TGW) Connect Ability Issues - CBR-2013 202404 Apr 2, 2024 · Service Bulletin/Repair Instructions
CBR: Turbo Compound (TC) Hot Side Noise, Diagnostic Information. - CBR-1008 202404 Apr 22, 2024 · Service Bulletin/Repair Instructions
CBR: Equipped With An Automated Manual Transmission Model D or F ( AMT-D, AMT-F, mDrive) Missing X1 Value In VDA And Default Settings Guidelines, ParameterP1AOB; Fault Code P1052-54, Error 40,Or Error 18 Encountered During Clutch Or Tran. - CBR-2258 202402 Feb 27, 2024 · Service Bulletin/Repair Instructions
CBR - Diagnostic Trouble Code (DTC) P107471 - AMT-F - M-834-001 202401 Jan 1, 2024 · Service Bulletin/Repair Instructions
TSB: Some Mack MMD trucks could experience an issue with the ignition lock cylinder sticking. Trucks that experience a sticking lock cylinder could have a lock cylinder that becomes tight or sticks in the start position. If the above condition is found re… - CBR-2342 202401 Jan 29, 2024 · Service Bulletin/Repair Instructions
CBR: Mack Medium Duty (MMD) Rear Suspension Bump Stop Bending - CBR-2333 202401 Jan 18, 2024 · Service Bulletin/Repair Instructions
CBR: TGW Will Not Connect After SIM Card Replacement - CBR-2016 202401 Jan 17, 2024 · Service Bulletin/Repair Instructions
CBR: Frame Or Cab Lean - M-465-001 202311 Nov 7, 2023 · Service Bulletin/Repair Instructions
TSB: Mack Trucks now offer an improved HD Inter-Axle Through Shaft for the CRD 125, 150, 180, and 200 family carriers. The new HD shaft went into production on January 23rd, 2023 for 2.54 - 3.50 axle ratios and April 1st, 2023 for 3.56 - 3.98 ratios. The ne… - CBR-2315 202309 Sep 29, 2023 · Service Bulletin/Repair Instructions
CBR: Mack Chassis - Medium Duty - Front Bumper License Plate Mounting Holes - M-258-014 202309 Sep 5, 2023 · Service Bulletin/Repair Instructions
TSB: Aftertreatment Diesel Exhaust Fluid (DEF) Tank, Level Sensor, Replacement - M-258-012 202309 Sep 5, 2023 · Service Bulletin/Repair Instructions
TSB: Aftertreatment Diesel Exhaust Fluid (DEF) Tank, Level Sensor, Replacement - M728-005A 202308 Aug 14, 2023 · Service Bulletin/Repair Instructions
TSB: Barksdale Leveling Valve, Leak Test - CBR-2112 202307 Jul 24, 2023 · Service Bulletin/Repair Instructions
CBR: Programming Failure - Chassis With Cummins Engine And An Allison Transmission - KC-474-Ver5 May 2, 2023 · Service Bulletin/Repair Instructions
CBR: Diagnostic Trouble Code (DTC) P215A-64, Fault Code SPN 84 FMI 19 - M-773-005a Apr 18, 2023 · Service Bulletin/Repair Instructions
TSB: Hub Cap, Leaking - M-773-005 Mar 16, 2023 · Service Bulletin/Repair Instructions
New TSB- Hub cap leaking - S7675 Dec 15, 2022 · Service Bulletin/Repair Instructions
MMD Incorrect Fuel Tank Label - S7669 Dec 15, 2022 · Service Bulletin/Repair Instructions
MMD Fan Hub Bolt Torque - KC-2218 Oct 31, 2022 · Service Bulletin/Repair Instructions
Mack Chassis - Parker F-3 Hydraulic Pump Installation - Model Year (MY) 2023 - M-265-002 Sep 22, 2022 · Service Bulletin/Repair Instructions
TSB-Charge Air Cooler t-clamp install. - CBR-2131 Aug 29, 2022 · Service Bulletin/Repair Instructions
USE FOR NEW VEHICLES (US21+OBD22 Emissions) - Intermittent Diagnostic Trouble Codes U02A3, U029D, U029E - KC-733 Jun 6, 2022 · Service Bulletin/Repair Instructions
Back Office Mack Chassis - Secondary Gauge Set Up - Model Year 2018 and Newer. - KC-2107 Jun 3, 2022 · Service Bulletin/Repair Instructions
DEF Level (UQLS) Sensor Troubleshooting Guide - US17+OBD16 Emissions and Newer. - KC-2112 Jun 21, 2022 · Service Bulletin/Repair Instructions
Programming Failure - Chassis With Cummins Engine And An Allison Transmission - KC-2116 Jun 3, 2022 · Service Bulletin/Repair Instructions
NOx Sensor Troubleshooting Guide - US10+OBD13 And Newer Emissions. - KC-2143 Jun 21, 2022 · Service Bulletin/Repair Instructions
(Back Office) - Cruise Control Inoperative After Updating Software VECU5 Without ESP Package (UESP). - KC-2157 Jun 3, 2022 · Service Bulletin/Repair Instructions
Aftertreatment Hydrocarbon Injector (AHI) Troubleshooting Guide - US10+OBD13 And Newer Emissions. - KC-2158 Jun 3, 2022 · Service Bulletin/Repair Instructions
Selective Catalytic Reduction (SCR) Muffler Troubleshooting Guide - US10+OBD13 And Newer Emissions. - KC-2165 Jun 3, 2022 · Service Bulletin/Repair Instructions
DEF Pump Troubleshooting Guide - US10+OBD13 And Newer Emissions. - KC-399 Jun 17, 2022 · Service Bulletin/Repair Instructions
Vehicle Overspeed Warning Comes Active At A Lower Speed Than Expected; Vehicle Overspeed Warning In Driver Information Display (DID) - Model Year 2018 And Newer With New Style Instrument Cluster. - KC-405 Jun 21, 2022 · Service Bulletin/Repair Instructions
Warranty Automated Manual Transmission ( AMT, I-Shift, mDrive ) Control Housing Assembly; Guidelines For Filing A Claim For Chassis Return Visit With Transmission Issues After A Repair Requiring Control Housing Removal And Reinstallation - US07 And N. - KC-561 Jul 5, 2022 · Service Bulletin/Repair Instructions
11L, 13L, And 16L Engine Oil Analysis Specifications - US10 And Newer Emissions - KC-735 Jun 6, 2022 · Service Bulletin/Repair Instructions
Premium Tech Tool (PTT) - Message For Data Mismatch, Product Configuration Mismatch; Instruction To Run An Accessory Kit Displayed When Attempting To Run Diagnostics For Diagnostic Trouble Codes (DTC) Or Programming - US10+OBD13 And Newer Emissions, - KC-736 Jun 6, 2022 · Service Bulletin/Repair Instructions
(Back Office Only) - Engine Brake Vibration When In High Setting - 13L Engine With Variable Geometry Turbo ( VGT ) - US17 And Newer Emissions (Common Rail Fuel System). - KC-745 Jun 22, 2022 · Service Bulletin/Repair Instructions
Automated Manual Transmission ( AMT ) I-Shift / mDRIVE - Ribbon Harness Replacement - Speed Sensor Bolts, Possible Fault Codes P1058 - 21 Or MID 130 PID 161 FMI 1 - KC-750 Jun 28, 2022 · Service Bulletin/Repair Instructions
US10 Emission Engines - Diagnostic Trouble Code ( DTC ) SPN 1231 FMI 9 Troubleshooting. - KC-751 Jun 28, 2022 · Service Bulletin/Repair Instructions
Vehicles Equipped With An Automated Manual Transmission Model D or F ( AMT-D, AMT-F ) - Transmission Oil Leakage From Transmission Input Shaft Seal Or Output Shaft Seal - US10 And Newer Emissions, Common Model Years 2010 And Newer. - KC-663 May 18, 2022 · Service Bulletin/Repair Instructions
Emcon (Spark Assist) Engine Aftertreatment System Troubleshooting Check Sheet - US07 Emissions - KC-644 May 17, 2022 · Service Bulletin/Repair Instructions
Manual Compression Test Adapter For Engines With Stainless Steel Injector Sleeves (Conical Tip Injectors) - US07 And Newer Emissions, Model Year 2008 And Newer - KC-627 May 9, 2022 · Service Bulletin/Repair Instructions
Premium Tech Tool ( PTT ) Training Materials And Support Tools - KC-2172 May 16, 2022 · Service Bulletin/Repair Instructions
No Start Condition After Over The Air Programing - VECU5 No Start "Safe State" - KC-2171 May 26, 2022 · Service Bulletin/Repair Instructions
Temperature Sensor Troubleshooting Guide - US10+OBD13 And Newer - KC-2170 May 16, 2022 · Service Bulletin/Repair Instructions
Electronically Controlled Suspension (ECS) Losing Air Pressure - KC-2169 May 16, 2022 · Service Bulletin/Repair Instructions
Low Voltage Disconnect (LVD), Function Description - KC-2165 May 26, 2022 · Service Bulletin/Repair Instructions
DEF Pump Troubleshooting Guide - US10+OBD13 And Newer Emissions - KC-2161 May 13, 2022 · Service Bulletin/Repair Instructions
DEF Pump Cycling periodically Hours After Key Off
Source: NHTSA manufacturer communications files.