RoadVitals

2027 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.
6
Latest Oct 1, 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 2027 Mack Pioneer Pr (4). 6 safety recalls have been issued covering this model year; and 48 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

6 campaigns cover this model year

View all 6

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
26V631000

STRUCTURE:BODY:BUMPERS:ACTIVE SHUTTERS/GRILL; STRUCTURE:EXTERIOR TRIM

Oct 1, 2026
3,096 units potentially affected
The 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.
The risk: A detached bezel can become a road hazard for other vehicles, increasing the risk of a crash.
The remedy: 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.
Mack Trucks, Inc.Manufacturer number SC0501View on NHTSA.gov
26V620000

SERVICE BRAKES, ELECTRIC:SOFTWARE/PROGRAMMING

Sep 28, 2026
850 units potentially affected
The defect: 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.
The remedy: Dealers will install new software to disable the dynamic trailer braking calculations, free of charge. Owner notification letters were mailed October 29, 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.
Mack Trucks, Inc.Manufacturer number SC0500View on NHTSA.gov
26V515000

EXTERIOR LIGHTING

Aug 6, 2026
513 units potentially affected
The defect: Mack Trucks, Inc. (Mack) is recalling certain 2027 Anthem AN (4) and Pioneer PR (4) vehicles. The center roof marker lights may fail to illuminate. 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: Marker lights that fail to illuminate can reduce visibility, increasing the risk of a crash.
The remedy: Dealers will replace the center roof marker light, free of charge. Interim letters notifying owners of the safety risk were mailed September 22, 2026. Additional letters will be sent once the final remedy is available. Owners may contact Mack's customer service at 1-800-866-1177. Mack's number for this recall is SC0498. Vehicle Identification Numbers (VINs) involved in this recall will be searchable on NHTSA.gov beginning August 13, 2026.
Mack Trucks, Inc.Manufacturer number SC0498View 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.

CBR 2408 202610

This document provides guidance for addressing the APM DTC C10129B fault, "High/Excessive Flow"

CBR 2532 202610

ELECTRICAL SYSTEM; EXTERIOR LIGHTING

The purpose of this CBR is to address issues of Automatic High Beam functionality. Automatic High Beam functionality has returned with the introduction of service packs (6.0-Volvo and 3.0-Mack).

CBR 2603 202610

ELECTRICAL SYSTEM

This document provides guidance for No-Crank/No-Start or Blank Instrument Cluster following shop programming or Over-The-Air (OTA) programming.

CBR 2598 202610

FUEL/PROPULSION SYSTEM

The purpose of this CBR is to provide steps on how to utilize the injector widget (within workshop toolbox) to aid with injection system issues.

TSB M-818-002 202610

STRUCTURE:BODY

Trucks equipped with large sleeper cab variants may experience vibration at speeds 62 - 70 mph when operating with an empty or lightly loaded trailer.

TSB M-258-017 202610

ENGINE; FUEL/PROPULSION SYSTEM

All Mack vehicles built with USA24, and forward emissions may experience damage to the diesel exhaust fluid pump harness due to wicking of DEF into the pump connector and harness. To prevent this issue an anti-wicking harness has been developed.

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
2027Viewing060—
2026090—
20250120—

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.