2026 Mack Pioneer Pr (4) problems

Defect

Mack Trucks, Inc. (Mack) is recalling certain 2026 Anthem (AN), 2026-2027 Pioneer PR (4), Pinnacle (PI/PN), Granite (GR), and 2027 Anthem AN (4) vehicles. The wheel lug nuts may loosen and allow the wheel to detach.

Consequence

Wheel detachment can cause a loss of vehicle control or create a road hazard, increasing the risk of a crash or injury.

Remedy

Owners are advised not to drive their vehicles until the repair has been performed. Dealers will inspect the wheel and hub mating surfaces, remove any masking material, and replace any worn components if necessary, free of charge. Owner notification letters were mailed June 22, 2026. Owners may contact Mack's customer service at 1-800-866-1177. Mack's number for this recall is SC0495. Vehicle Identification Numbers (VINs) involved in this recall became searchable on NHTSA.gov on May 31, 2026.

Defect

Mack Trucks, Inc. (Mack) is recalling certain 2025-2027 Pioneer (4) and 2026-2027 Anthem (4) vehicles. The rear brake modulators may have unprotected electrical connectors that can short circuit and lead to a loss of the anti-lock brake system (ABS) and electronic stability control (ESC).

Consequence

A loss of anti-lock brakes and electronic stability control increases the risk of a crash or injury.

Remedy

Dealers will inspect the rear brake modulator electrical connectors, install a protective cover, and replace the rear brake modulators, as necessary, free of charge. Owner notification letters were mailed June 8, 2026. Owners may contact Mack's customer service at 1-800-866-1177. Mack's number for this recall is SC0494. Vehicle Identification Numbers (VINs) involved in this recall will be searchable on NHTSA.gov beginning April 30, 2026.

Defect

Mack Trucks, Inc. (Mack) is recalling certain 2025-2027 Pioneer (4) and 2027 Anthem (4) trailers. The trailer turn signals may not function properly. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard number 108, "Lamps, Reflective Devices, and Associated Equipment."

Consequence

Turn signals that do not function properly may fail to indicate the driver's intention to change vehicle direction, increasing the risk of a crash.

Remedy

Dealers will update the turn signal indicator software, free of charge. Owner notification letters were mailed May 7, 2026. Owners may contact Mack's customer service at 1-800-866-1177. Mack's number for this recall is SC0493. Vehicle Identification Numbers (VINs) involved in this recall became searchable on NHTSA.gov April 1, 2026.

Defect

Mack Trucks, Inc. (Mack) is recalling certain 2026 Anthem (4) and 2025-2026 Pioneer vehicles. The automatic high beams (AHB) may not switch to low beam headlights as intended. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard number 108, "Lamps, Reflective Devices, and Associated Equipment."

Consequence

High beam headlights that do not switch to low beam as intended can reduce visibility for oncoming traffic, increasing the risk of a crash.

Remedy

As an interim action, Mack will update the vehicle software through an over-the-air (OTA) update to disable the AHB feature, free of charge. Owner letters were mailed May 29, 2026. Owners may contact Mack's customer service at 1-800-866-1177. Mack's number for this recall is SC0488. Vehicle Identification Numbers (VINs) involved in this recall will be searchable on NHTSA.gov beginning November 27, 2025.

Defect

Mack Trucks, Inc. (Mack) is recalling certain 2025-2026 Pioneer vehicles. The load lock clamps, located on the back of the cab, may loosen and cause the load lock bars to become unsecured.

Consequence

A loose or unsecured load lock bar can result in a loss of cargo, creating a road hazard and increasing the risk of a crash.

Remedy

Dealers will replace the load lock clamps, free of charge. Owner notification letters were mailed December 18, 2026. Owners may contact Mack's customer service at 1-800-866-1177. Mack's number for this recall is SC0489. Vehicle Identification Numbers (VINs) involved in this recall will be searchable on NHTSA.gov beginning November 27, 2025.

Defect

Mack Trucks, Inc. (Mack) is recalling certain 2025-2026 Pioneer vehicles. When towing a trailer, the trailer lights may fail to illuminate due to an improperly manufactured body control module.

Consequence

Trailer tail lights and turn signals that do not illuminate as intended can reduce visibility to other drivers, increasing the risk of a crash.

Remedy

Dealers will replace the trailer body input/output module, free of charge. Owner letters were mailed November 19, 2025. Owners may contact Mack's customer service at 1-800-866-1177. Mack's number for this recall is SC0484.Vehicle Identification Numbers (VINs) involved in this recall will be searchable on NHTSA.gov beginning September 25, 2025.

Defect

Mack Trucks, Inc. (Mack) is recalling certain 2025 Anthem and 2025-2026 Pioneer vehicles. The dynamic steering and oversteer guidance feature may malfunction and cause a loss of steering control.

Consequence

A loss of steering control increases the risk of a crash.

Remedy

The oversteer guidance feature will be disabled through an over-the-air (OTA) update or by a dealer, free of charge. Owner notification letters were mailed August 21, 2025. Owners may contact Mack's customer service at 1-800-866-1177. Mack's number for this recall is SC0483.