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Service bulletins for the 2025 Mack Pioneer

A bulletin is a manufacturer's communication to its dealers, as NHTSA indexes it. The summary is NHTSA's. The document is the manufacturer's: read it at NHTSA. A bulletin is not a recall, and listing a model year does not mean every vehicle of it is concerned.

155 on file from NHTSA, as of 2026-10-19.

By type

By component

By trouble code

Bulletins, newest first
CBR 407 0720252025-08-04. Service bulletin. SERVICE BRAKES; ELECTRICAL SYSTEM. CBR - To correct the MID136 SID 66 FMI 7 fault code the latest Bendix VCP file will need to downloaded.
CBR 2488 0720252025-08-04. Service bulletin. ELECTRICAL SYSTEM. CBR - A significant GPS reporting issue is affecting fleet operations, with trucks maintaining back-office communication but failing to transmit GPS location data.
CBR 2483 0720252025-08-04. Service bulletin. ELECTRICAL SYSTEM. CBR - This CBR solution outlines the diagnosis and resolution of a DL6 CAN bus resistance issue, where a 40-ohmreading causes ELD communication failure, corrected by disconnecting the SCIM A262.D connector.
CBR 2482 0720252025-08-04. Service bulletin. POWER TRAIN. CBR - Purpose of this CBR is to address Pop up message for PTO Malfunction when there is not PTO Installed.
CBR -2467-4 0720252025-08-04. Service bulletin. ELECTRICAL SYSTEM. CBR - This CBR solution was created to􀁡provide guidance on resolving the “Service Required” message that may appear in the Instrument Cluster (IC) of VN (4) and PR (4) model vehicles under specific conditions.
CBR 2465-2 0720252025-08-04. Service bulletin. ELECTRICAL SYSTEM; UNKNOWN OR OTHER. CBR - This CBR pertains to two issues that may arise with the Proactive Engine Restart (Remote Engine Start System).
CBR 2447 0720252025-08-04. Service bulletin. SUSPENSION. CBR - Electronically Controlled Suspension (ECS) calibration using Premium Tech Tool (PTT) is required to correct discrepancies between the cluster load indicator and actual scale values, ensuring proper functionality of liftable axles and preventing unintended axle behavior.
CBR 2443 0720252025-08-04. Service bulletin. ELECTRICAL SYSTEM; SERVICE BRAKES. CBR - The truck’s trailer detection system uses a brief pulse of compressed air through the red trailer supply line to detect a connected trailer, but this pulse can inadvertently re-lock air-actuated tandem slide systems; this procedure outlines a method to mitigate the issue while sliding the trailer tandems.
CBR 2431 0720252025-08-04. Service bulletin. FUEL/PROPULSION SYSTEM. CBR - This CBR solution addresses crank no start and engine dying issues in some VN (4) and PR (4) models caused by an incorrect fuel line configuration and/or fuel line fitting not seated correctly.
CBR 2429-3 0720252025-08-04. Service bulletin. ELECTRICAL SYSTEM. CBR - This CBR solution outlines the procedures for diagnosing, replacing, calibrating, and programming Flexible Switch Panels and the Security and Cab Interface Module (SCIM) to resolve switch malfunction notifications and associated fault codes.
CBR 2425 0720252025-08-04. Service bulletin. FUEL/PROPULSION SYSTEM. CBR - This CBR solution outlines the analysis of temperature changes in sensors T1, T2, and T3 and provides a procedure for inspecting and addressing potential sensor issues related to AHI fuel injection.
CBR 2408 0720252025-08-04. Service bulletin. SERVICE BRAKES. CBR - This document provides guidance for addressing the Air Production􀁡Modulator (APM) DTC C10129B fault, "High/Excessive Flow" This fault was introduced by a previous APM software package and requires specific containment actions.
CBR 2396 0720252025-08-04. Service bulletin. ELECTRICAL SYSTEM; UNKNOWN OR OTHER. CBR - For newly delivered vehicles it may be found that the key fob will not unlock the door. The message "Pre-delivery Mode" maybe displayed on the instrument cluster.
CBR 2330 0720252025-08-04. Service bulletin. ENGINE. CBR - Mechanical components with moving parts designed for high-temperature environments – such as the turbo wastegate used on the 13L TC engines – are susceptible to certain kinds of leakages due to their design requirements.
CBR 2474-1 2025062025-07-01. Service bulletin. POWER TRAIN. CBR - This bulletin provides guidance for identifying and addressing oil intrusion related to the Countershaft Brake (CSB) in AMT-G transmissions.
CBR 2472-2 2025052025-06-02. Service bulletin. ELECTRICAL SYSTEM. The purpose of this CBR is to provide instructions when trying to retrieve DTC and a Communication Failed Popup occurs.
CBR 2468-2 2025052025-06-02. Service bulletin. ELECTRICAL SYSTEM. The purpose of this CBR is to help diagnosis an electrically faulty door latch.
CBR 2107-21 2025052025-06-02. Service bulletin. FUEL/PROPULSION SYSTEM; ENGINE. Mack DEF Level (UQLS) Sensor Troubleshooting Guide - US17+OBD16 Emissions and Newer
CBR 2463-3 2025042025-05-05. Service bulletin. ENGINE. CBR - The purpose of this CBR is to assist in determining source(s) of suspect abnormal turbocharger noise.
CBR-2452 2025032025-04-02. Service bulletin. ELECTRICAL SYSTEM. If the vehicle door is open and the truck is in neutral, a popup message may appear on the Driver Information Display (DID) instructing the operator to shift into neutral. If this message appears while the vehicle is already in neutral, the Instrument Cluster (IC)requires a software update.
CBR-561 2025032025-04-02. Service bulletin. ENGINE. If oil dilution is suspected refer to the applicable CBR solution below: ∙ CBR-659􀁡Mack Chassis - Oil Diluted With Fuel; Fuel In Oil, Diagnostic Information - All Emissions, All Model Years
S4373-2025022025-03-03. Service campaign. STRUCTURE:BODY; UNKNOWN OR OTHER. Mack Trucks has determined that certain Mack sleeper cab assemblies were possibly manufactured with an insufficient number of welds across the rear flange of the upper header. The reduced number of welds could lower the designed cab integrity.
S4342-2025022025-03-03. Service bulletin. FUEL/PROPULSION SYSTEM; ENGINE. Mack Trucks has determined that a select group of trucks were built with an AHI Module fuel pressure sensor which does not meet our specifications.
CBR-2016 2024122025-01-02. Service bulletin. SUSPENSION. Frame lean can be caused by several seemingly isolated possibilities. The two most common are suspension and frame assembly issues.
CBR-997 2024112024-12-02. Service bulletin. ENGINE. Vehicles may present with oil leak coming from the clutch/flywheel housing and observation of burned clutch smell or clutch slipping. These symptoms can be mistaken as a crankshaft rear main seal leak, when the actual cause is the crankshaft adaptor O-ring.

The summaries are NHTSA's. Each bulletin's page links NHTSA's copy of the manufacturer's document.