2025 Mack Pioneer Pr (4) problems, complaints & recalls
Safety recalls (12)
Structure:body:bumpers:active Shutters/Grill 2026-10-01 · campaign 26V631000 · 3,096 vehicles
Defect: Mack Trucks, Inc. (Mack) is recalling certain 2026-2027 Anthem AN (4) and 2025-2027 Pioneer PR (4) vehicles. The intake and grille bezels may detach from the vehicle.
Risk: A detached bezel can become a road hazard for other vehicles, increasing the risk of a crash.
Fix: Dealers will inspect, replace the intake and grille bezels, and install cable ties as necessary, free of charge. Owner notification letters are expected to be mailed November 30, 2026. Owners may contact Mack's customer service at 1-800-866-1177. Mack's number for this recall is SC0501. Vehicle Identification Numbers (VINs) involved in this recall will become searchable on NHTSA.gov on October 8, 2026.
Service Brakes, Air:antilock:control Unit/Module 2026-04-23 · campaign 26V261000 · 2,772 vehicles
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).
Risk: A loss of anti-lock brakes and electronic stability control increases the risk of a crash or injury.
Fix: 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.
Exterior Lighting:turn Signal 2026-04-01 · campaign 26V207000 · 86 vehicles
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."
Risk: 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.
Fix: 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.
Equipment:mechanical 2025-11-20 · campaign 25V801000 · 46 vehicles
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.
Risk: 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.
Fix: 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.
Exterior Lighting:lighting Control Module:software 2025-11-20 · campaign 25V803000 · 247 vehicles
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."
Risk: High beam headlights that do not switch to low beam as intended can reduce visibility for oncoming traffic, increasing the risk of a crash.
Fix: 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.
Exterior Lighting:lighting Control Module 2025-09-18 · campaign 25V622000 · 156 vehicles
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.
Risk: Trailer tail lights and turn signals that do not illuminate as intended can reduce visibility to other drivers, increasing the risk of a crash.
Fix: 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.
Steering 2025-08-11 · campaign 25V521000 · 32 vehicles
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.
Risk: A loss of steering control increases the risk of a crash.
Fix: 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.
Service Brakes, Air:supply:reservoir/Tank 2025-01-21 · campaign 25V026000 · 21 vehicles
Defect: Mack Trucks, Inc. (Mack) is recalling certain 2024-2025 Pinnacle (PI/PN) trucks. The air tanks have an insufficient volume of air for the brake system. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard number 121, "Air Brake Systems."
Risk: Insufficient air volume can reduce braking performance and increase the risk of a crash.
Fix: Dealers will install the correct volume air tanks, free of charge. Owner notification letters were mailed February 10, 2025. Owners may contact Mack's customer service at 1-800-866-1177. Mack's number for this recall is SC0473.
Electrical System:software 2024-10-23 · campaign 24V792000 · 59,338 vehicles
Defect: Mack Trucks, Inc. (Mack) is recalling certain 2020-2025 Anthem, Granite, TerraPro and Pinnacle vehicles, equipped with Bendix EC80 Advanced Electronic Control Units (ECU). Electrical noise and low signal to the power line carrier may cause the ECU to incorrectly process commands or stop working.
Risk: Safety systems that depend on the ECU (Automatic Traction Control, ABS, Electronic Stability Control, Active Cruise Control, and Collison Mitigation System) may have diminished or lost functionality, increasing the risk of a crash.
Fix: Dealers will reprogram the ECU software, free of charge. Owner notification letters were mailed December 9, 2024. Owners may contact Mack customer service at 1-800-866-1177. Mack's number for this recall is SC0472.
Seats:critical Fasteners 2024-07-30 · campaign 24V567000 · 242 vehicles
Defect: Mack Trucks, Inc. (Mack) is recalling certain 2024-2025 Anthem, Granite, and Pinnacle vehicles equipped with RollTek driver's seat assemblies. The seat pedestal and seat belt attachment may have been improperly tightened.
Risk: An improperly tightened seat pedestal and seat belt attachment may not restrain the occupant as intended, increasing their risk of injury during a crash.
Fix: Dealers will replace and tighten the seat pedestal and seat belt attachment bolts, free of charge. Owner notification letters were mailed September 16, 2024. Owners may contact Mack customer service at 1-800-866-1177. Mack's number for this recall is SC0469.
Steering:linkages:tie Rod Assembly 2024-07-02 · campaign 24V504000 · 59 vehicles
Defect: Mack Trucks, Inc. (Mack) is recalling certain 2025 LR, Granite, and Pinnacle vehicles equipped with Composilite EXS20 steerable lift axle suspension assemblies. The tie rod assembly ball stud could have been improperly heat treated and can fail.
Risk: The ball stud can separate from the vehicle becoming a road hazard, increasing the risk of a crash.
Fix: Dealers will inspect and replace the tie rod end assemblies as necessary, free of charge. Owner notification letters were mailed July 15, 2024. Owners may contact Mack customer service at 1-800-866-1177. Mack's number for this recall is SC0468.
Power Train:axle Assembly 2024-06-09 · campaign 24V424000 · 7 vehicles ⚠ DO NOT DRIVE
Defect: Mack Trucks, Inc. (Mack) is recalling certain 2025 Anthem and Pinnacle trucks. The tie rod assemblies may contain an improperly heat-treated ball stud that can fail, resulting in a sudden loss of steering control.
Risk: A sudden loss of steering control increases the risk of a crash.
Fix: Owners are advised not to drive their vehicles until the remedy has been completed. Dealers will inspect and replace the tie rod ends as necessary, free of charge. Owner notification letters were mailed June 17, 2024. Owners may contact Mack customer service at 1-800-866-1177. Mack's number for this recall is SC0466.
Service bulletins (155)
Technical service bulletins are repair instructions manufacturers send dealers for known issues. Unlike recalls, the fix is not automatically free — but naming the bulletin at the service desk can save diagnosis time and support goodwill repairs.
Electrical System 2026-09-27 · TSB M-373-003 202609 · Service Bulletin/Repair Instructions
power cable alternator replacement
Electrical System 2026-09-24 · CBR 2590-3 202609 · Service Bulletin/Repair Instructions
instrument cluster going dark
Electrical System 2026-09-17 · CBR 2483-6 202609 · Service Bulletin/Repair Instructions
diagnostic instructions for can network communication issues.
Electrical System 2026-09-08 · CBR 2496-18 202609 · Service Bulletin/Repair Instructions
the purpose of this cbr is outline the interim software solution for pr(4) and an(4).
Electrical System 2026-09-01 · TSB M-371-005A 202609 · Service Bulletin/Repair Instructions
jumper harness repair for version 4 mack trucks
Engine 2026-08-26 · TSB M257005 202608 · Service Bulletin/Repair Instructions
loose ccv mounting bolts and oil leak at ccv due to cracking of the housing. mounting hardware found to be under-torqued after the vehicle was delivered.
Showing the 6 most recent of 155 bulletins. Search all of them free at nhtsa.gov.
What owners report
No detailed complaint narratives on file.
Excerpts of consumer complaints filed with NHTSA, lightly truncated. They are owner statements, not verified findings.