RoadVitals

2026 Mack Pioneer Pr (4)

Recalls, owner-reported complaints, investigations and safety data

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

Campaign 26V351000. 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.
7
Latest May 28, 2026
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 2026 Mack Pioneer Pr (4). 7 safety recalls have been issued covering this model year; and 89 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

7 campaigns cover this model year

View all 7

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
26V351000NHTSA advisory: do not drive

WHEELS:LUGS/NUTS/BOLTS/STUDS

May 28, 2026
644 units potentially affected
The 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.
The risk: Wheel detachment can cause a loss of vehicle control or create a road hazard, increasing the risk of a crash or injury.
The 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.
Mack Trucks, Inc.Manufacturer number SC0495View on NHTSA.gov
26V261000

SERVICE BRAKES, AIR:ANTILOCK:CONTROL UNIT/MODULE

Apr 23, 2026
2,772 units potentially affected
The 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).
The risk: A loss of anti-lock brakes and electronic stability control increases the risk of a crash or injury.
The 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.
Mack Trucks, Inc.Manufacturer number SC0494View on NHTSA.gov
26V207000

EXTERIOR LIGHTING:TURN SIGNAL

Apr 1, 2026
86 units potentially affected
The 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."
The 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.
The 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.
Mack Trucks, Inc.Manufacturer number SC0493View 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.

TSB M-590-001 072026

SERVICE BRAKES

TSB - Wheel Speed Sensor Fitting And Cable Clamping.

CBR 2585-3 072026

ELECTRICAL SYSTEM

CBR - The purpose of this CBR is to provide support for fault codes C106718 and/or C106818.

CBR 2545-3 072026

ELECTRICAL SYSTEM

CBR - The purpose of this CBR is to provide guidance on fault code U114688.

CBR-2590-2 202606

ELECTRICAL SYSTEM

The purpose of this CBR is to provide steps on how to correct a customer complaint of instrument cluster going dark (blackout) situation.

CBR-2591-1 202606

ENGINE

The purpose of this CBR it to provide release notes for the recent Engine ECU software.

CBR-2568-5 202606

ELECTRICAL SYSTEM

Contact Workshop; Communication Lost With Ultracapacitor Message With Associated CCIOM DTC U100687 And A Startability Issue.

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 Pioneer Pr (4) by model year
YearComplaintsRecallsInvestigationsIssue Index
2027040—
2026Viewing070—
20250110—

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.