2026 Mack Pioneer PR (4): recalls and complaints

NHTSA advisory: do not driveCampaign 26V351000. NHTSA received the report on 28 May 2026. 644 units. Wheels / Lugs/Nuts/Bolts/Studs

Remedy of campaign 26V351000, in the NHTSA record

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.

Do-not-drive advisory: A mark on a recall campaign in the NHTSA recall file. This site shows the mark as NHTSA sets it.

NHTSA lists 8 recall campaigns for the 2026 Mack Pioneer PR (4). The newest campaign is 26V620000. NHTSA received the report on 28 Sep 2026. The NHTSA record gives the component Service Brakes, Electric / Software/Programming. NHTSA has no complaint on file for this model year.

This page cannot show if a recall applies to one vehicle. The NHTSA VIN lookup shows the unrepaired recalls of one vehicle.

Remedy of the newest campaign, 26V620000, in the NHTSA record

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.

NHTSA VIN lookup

Complaint information entered into NHTSA’s Office of Defects Investigation vehicle owner's complaint database is used with other data sources to identify safety issues that warrant investigation and to determine if a safety-related defect trend exists.
NHTSA publishes these words. Source: NHTSA Datasets and APIs, section Complaints, read on 1 Oct 2026. Complaint file through 30 Sep 2026. Recall file through 30 Sep 2026.

Since the last update

No tracked figure of this page changed in a data update. What the log tracks

All updates to the register

Recall campaigns

8 campaigns, newest first. 4,833 units in total.

26V62000028 Sep 2026Service Brakes, Electric / Software/Programming
26V35100028 May 2026Wheels / Lugs/Nuts/Bolts/StudsAdvisory
26V26100023 Apr 2026Service Brakes, Air / Antilock / Control Unit/Module
26V2070001 Apr 2026Exterior Lighting / Turn Signal
25V80100020 Nov 2025Equipment / Mechanical
25V80300020 Nov 2025Exterior Lighting / Lighting Control Module / Software
25V62200018 Sep 2025Exterior Lighting / Lighting Control Module
25V52100011 Aug 2025Steering

26V620000Received 28 Sep 2026. 850 units.
Service Brakes, Electric / Software/Programming
Defect, in the NHTSA record
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.
Consequence, in the NHTSA record
Reduced braking performance can require a greater distance to stop, increasing the risk of a crash.
Remedy, in the NHTSA record
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.
Report filed by Mack Trucks, Inc.. Manufacturer campaign number SC0500.
26V351000Received 28 May 2026. 644 units.
Wheels / Lugs/Nuts/Bolts/StudsDo-not-drive advisory
Defect, in the NHTSA record
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, in the NHTSA record
Wheel detachment can cause a loss of vehicle control or create a road hazard, increasing the risk of a crash or injury.
Remedy, in the NHTSA record
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.
Report filed by Mack Trucks, Inc.. Manufacturer campaign number SC0495. Owner notification date in the NHTSA record: 17 Jun 2026.
26V261000Received 23 Apr 2026. 2,772 units.
Service Brakes, Air / Antilock / Control Unit/Module
Defect, in the NHTSA record
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, in the NHTSA record
A loss of anti-lock brakes and electronic stability control increases the risk of a crash or injury.
Remedy, in the NHTSA record
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.
Report filed by Mack Trucks, Inc.. Manufacturer campaign number SC0494. Owner notification date in the NHTSA record: 8 Jun 2026.
26V207000Received 1 Apr 2026. 86 units.
Exterior Lighting / Turn Signal
Defect, in the NHTSA record
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, in the NHTSA record
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, in the NHTSA record
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.
Report filed by Mack Trucks, Inc.. Manufacturer campaign number SC0493. Owner notification date in the NHTSA record: 8 May 2026.
25V801000Received 20 Nov 2025. 46 units.
Equipment / Mechanical
Defect, in the NHTSA record
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, in the NHTSA record
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, in the NHTSA record
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.
Report filed by Mack Trucks, Inc.. Manufacturer campaign number SC0489. Owner notification date in the NHTSA record: 18 Dec 2025.
25V803000Received 20 Nov 2025. 247 units.
Exterior Lighting / Lighting Control Module / Software
Defect, in the NHTSA record
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, in the NHTSA record
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, in the NHTSA record
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.
Report filed by Mack Trucks, Inc.. Manufacturer campaign number SC0488. Owner notification date in the NHTSA record: 29 May 2026.
25V622000Received 18 Sep 2025. 156 units.
Exterior Lighting / Lighting Control Module
Defect, in the NHTSA record
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, in the NHTSA record
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, in the NHTSA record
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.
Report filed by Mack Trucks, Inc.. Manufacturer campaign number SC0484. Owner notification date in the NHTSA record: 19 Nov 2025.
25V521000Received 11 Aug 2025. 32 units.
Steering
Defect, in the NHTSA record
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, in the NHTSA record
A loss of steering control increases the risk of a crash.
Remedy, in the NHTSA record
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.
Report filed by Mack Trucks, Inc.. Manufacturer campaign number SC0483. Owner notification date in the NHTSA record: 21 Aug 2025.

The campaign number opens the NHTSA record. Each quotation is the text of the NHTSA recall file.

Recall campaign: One recall in the NHTSA recall file, with one campaign number. A campaign can name many makes, models and model years.

Units: The number of vehicles or products that a recall can include. The manufacturer or the firm reports the number to the agency.

Complaints by component

The NHTSA complaint file has no complaint for this model year.

Investigations

The NHTSA investigation file has no investigation that names this model year.

Investigation: A study of a possible safety defect by the NHTSA Office of Defects Investigation. An investigation with no closing date in the NHTSA file is open.

Other model years

The number under each year is the number of recall campaigns.

A year without a link has fewer than 2 campaigns and fewer than 25 complaints. It has no page.

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Official channels

NHTSA VIN lookupNHTSA shows the unrepaired recalls of one vehicle from its VIN or its license plate.
NHTSA: report a safety problemThe NHTSA form for a complaint about a vehicle, a tire, a child seat or equipment.
NHTSA page of the 2026 Mack Pioneer PR (4)The recalls, the complaints and the investigations that NHTSA shows for this model year.

Cite this page

Recall Register. 2026 Mack Pioneer PR (4): recalls and complaints. https://recallregister.com/vehicle/mack/pioneer-pr-4/2026/. Source: NHTSA Office of Defects Investigation, recall, complaint and investigation files. Data through 30 Sep 2026.

Sources

Source: NHTSA Office of Defects Investigation
Licence: US government work, public domain
Recall file through: 30 Sep 2026
Complaint file through: 30 Sep 2026
First complaint in the file: 1 Jan 1995
Manufacturer in the recall file: Mack Trucks, Inc.

The NHTSA record is the authority. A complaint count is the number of different complaint numbers for the make, the model and the model year. How the register is made. Report an error.

Questions

How many units are in the recall campaigns for the 2026 Mack Pioneer PR (4)?: 4,833 units in 8 campaigns. A campaign can name other models and model years, and its units include them.
How many recall campaigns does the Mack Pioneer PR (4) have for all model years?: NHTSA lists 14 recall campaigns for the Mack Pioneer PR (4), model years 2025 to 2027. 8 of them name the 2026 model year.
Is an NHTSA investigation of the 2026 Mack Pioneer PR (4) open?: The NHTSA investigation file has no investigation that names this model year.