RoadVitals

2021 Mack Md

Recalls, owner-reported complaints, investigations and safety data

NHTSA has issued a “do not drive” advisory affecting this model year.

Campaign 21V684000. Confirm whether your specific vehicle is covered using its VIN before acting on this.

Check your VIN on NHTSA.gov
Owner complaintsComplaints are reports submitted to NHTSA by owners and drivers. NHTSA does not verify most reports before publishing them, and a complaint does not establish that a defect exists. Volume is influenced by how many of a vehicle were sold, how long it has been on the road, and how much attention an issue has received.
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Safety recallsA safety recall is issued when a manufacturer or NHTSA determines that a vehicle has a safety-related defect or does not comply with a federal motor vehicle safety standard. Recall repairs are free. Whether a specific vehicle is covered depends on its VIN — a recall listed for a model year does not necessarily apply to every vehicle of that year.
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Latest Oct 6, 2025
InvestigationsNHTSA opens an investigation to examine whether a safety defect may exist. An open investigation is not a determination that a defect exists, and many investigations close without a recall. Investigations can, however, lead to one.
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Crash or fire reportedComplaints whose submitter recorded that a crash or a fire occurred. These are the reporter's own answers on the NHTSA form, not verified findings.
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Overview

Our database contains no NHTSA owner-reported complaints for the 2021 Mack Md. 2 safety recalls have been issued covering this model year; and 112 manufacturer communications are on file.

Complaints are reports submitted by owners and drivers to NHTSA. They are not verified and do not establish that a defect exists.

Safety recalls

2 campaigns cover this model year

Recalls apply to specific vehicles, not to every vehicle of a model year. Check your VIN with NHTSA or your manufacturer's dealer to confirm whether a recall affects your vehicle.

Check a VIN on NHTSA.gov
25V666000

SEAT BELTS:FRONT:ANCHORAGE

Oct 6, 2025
15,841 units potentially affected
The defect: Mack Trucks, Inc. (Mack) is recalling certain 2020-2025 Mack MD, 2019-2025 Anthem, Granite, 2024 MD Electric, and 2025 Pinnacle trucks equipped with a passenger bench seat. The seat belt anchorage bracket may be improperly welded. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard number 210, "Seat Belt Assembly Anchorages."
The risk: An improperly welded seat belt anchorage bracket can detach during a crash, increasing the risk of injury.
The remedy: Dealers will install a reinforcement plate, free of charge. Owner letters were mailed January 21, 2026. Owners may contact Mack's customer service at 1-800-866-1177. Mack's number for this recall is SC0485. Vehicle Identification Numbers (VINs) involved in this recall will be searchable on NHTSA.gov beginning October 13, 2025.
Mack Trucks, Inc.Manufacturer number SC0485View on NHTSA.gov
21V684000NHTSA advisory: do not drive

SERVICE BRAKES, HYDRAULIC:PEDALS AND LINKAGES

Sep 1, 2021
2,823 units potentially affected
The defect: Mack Trucks, Inc. (Mack) is recalling certain 2020-2022 Mack MD vehicles. The cotter pin that retains the brake pedal clevis pin may not have been properly installed, which could result in an unsecured brake pedal.
The risk: An unsecured brake pedal can cause a loss of braking ability and increase the risk of a crash.
The remedy: Owners are advised to not drive their vehicles until the remedy has been performed. Dealers will inspect the cotter pin installation and repair it as necessary, free of charge. Owner notification letters were mailed on September 13, 2021. Owners may contact Mack's customer service at 1-800-866-1177. Mack's number for this recall is SC0429.
Mack Trucks, Inc.Manufacturer number SC0429View on NHTSA.gov

Recent owner complaints

Reports submitted to NHTSA, shown in the owner's own words

No owner complaints recorded for this model year

Either none have been filed with NHTSA, or this vehicle is too new for reports to have accumulated.

Manufacturer communications

A bulletin sent by a manufacturer to its dealers. Not a recall, and repairs are not necessarily free.

CBR 2573-1 202604

POWER TRAIN

CBR - Mack Chassis - Through Shaft Bearing Retainer Breakage On Mack Carriers.

CBR 2362-3 202604

POWER TRAIN

CBR - Mack Carrier Nut Adhesive Change.

CBR 2712-7 032026

ELECTRICAL SYSTEM

CBR - No Start Condition After Over the Air Programing.

TSB M-432-002A 032026

POWER TRAIN

TSB - Cable, Gear Selector, Replacement

CBR 2107-22 202601

ENGINE

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

ELECTRICAL SYSTEM

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.

Manufacturers file copies of the bulletins they send to dealers with NHTSA. These often describe diagnostic or repair procedures for a known condition. They are not recalls: repairs described in a bulletin are usually only free if the vehicle is still under warranty or the manufacturer has extended coverage.

Compare model years

Complaint and recall counts across every year of this model

Mack Md by model year
YearComplaintsRecallsInvestigationsIssue Index
2027000—
2026010—
2025120—
2024050—
2023120—
2022030—
2021Viewing020—
2020020—

Higher-selling and older vehicles accumulate more reports. Counts are not failure rates and are not directly comparable between vehicles that sold in very different numbers. Older model years have had longer for reports to accumulate.