Mack recall 26V-620: Software Calculation Error May Cause Reduced Braking Performance
Reduced braking performance can require a greater distance to stop, increasing the risk of a crash.
Campaign facts
- NHTSA campaign
- 26V620000 (26V-620)
- Manufacturer number
- SC0500
- Filed by
- Mack Trucks, Inc.
- Report received
- September 28, 2026
- Component
- Service brakes, electric:software/programming
- Vehicles potentially affected
- 850
- Model years
- 2026–2027
- Built between
- February 24, 2025 and September 26, 2026
- Recall initiated by
- The manufacturer
What is wrong
Mack Trucks, Inc. (Mack) is recalling certain 2026-2027 Anthem AN (4) and Pioneer PR (4) vehicles equipped with a tanker application package. Inaccurate axle load calculations may cause reduced braking performance while transporting smoothbore tanker trailers.
The risk
Reduced braking performance can require a greater distance to stop, increasing the risk of a crash.
Why brake defects matter: Reduced braking or a loss of brake assist lengthens stopping distance and increases the risk of a crash.
The remedy
Dealers will install new software to disable the dynamic trailer braking calculations, free of charge. Owner notification letters are expected to be mailed November 27, 2026. Owners may contact Mack's customer service at 1-800-866-1177. Mack's number for this recall is SC0500. Vehicle Identification Numbers (VINs) involved in this recall will become searchable on NHTSA.gov on October 5, 2026.
About the brakes
The service brakes are the system you use every time you press the pedal — hydraulic or air components plus the electronic controls that manage them.
Vehicles covered by campaign 26V-620
- Mack Anthem An (4) 20272026
- Mack Pioneer Pr (4) 20272026
What to do
- Enter your VIN in NHTSA’s lookup (below) to confirm that your vehicle is included and that the repair has not already been done.
- Call a dealer for the brand and book the repair. Quote NHTSA campaign 26V-620 and the manufacturer’s number SC0500.
- If a brake warning lamp comes on or the pedal feels different, have the vehicle inspected before you keep driving it.
- Safety recall repairs are carried out free of charge by the manufacturer’s dealers. If you already paid for this repair yourself, ask the manufacturer about reimbursement and keep your receipt.
Check by VIN
A campaign rarely covers every vehicle of a model year. Enter your 17-character VIN to find the recall campaigns filed for your make, model and model year. The VIN is on the driver’s side of the dashboard (visible through the windshield), on the door-jamb label, and on your registration and insurance documents.
Is a recall still open on your vehicle? Only NHTSA’s official VIN check can say whether a campaign applies to your exact vehicle and whether the repair has already been done.
Your VIN is decoded with NHTSA’s public vPIC service to identify the make, model and year. It is not stored and is not added to any page address.
The official record
This page reproduces the campaign as filed with NHTSA. The NHTSA record is authoritative — if anything here differs, follow the agency.
Open campaign 26V-620 on NHTSA.gov