WenmarOpen by Wenmar Pro

Service bulletins for the 2026 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.

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

By type

By component

By trouble code

By topic

Bulletins, newest first
TSB M-371-005A 2026092026-10-02. Service bulletin. ELECTRICAL SYSTEM. Jumper Harness Repair for Version 4 Mack Trucks
TSB M-373-003 2026092026-10-02. Service bulletin. ELECTRICAL SYSTEM. Power Cable Alternator Replacement
CBR 2590-3 2026092026-10-02. Service bulletin. ELECTRICAL SYSTEM. Instrument Cluster Going Dark
CBR 2496-18 2026092026-10-02. Service bulletin. ELECTRICAL SYSTEM. The purpose of this CBR is outline the interim software solution for PR(4) and AN(4).
CBR 2483-6 2026092026-10-01. Service bulletin. ELECTRICAL SYSTEM. Diagnostic instructions for CAN network communication issues.
TSB M257005 2026082026-09-01. Service bulletin. ENGINE. 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.
CBR 2599 2026082026-09-01. Service bulletin. SERVICE BRAKES. The purpose of this CBR is to provide support for complaints of trailer braking aggressively.
CBR 2598 2026082026-09-01. Service bulletin. 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.
CBR 2597 2026082026-09-01. Service bulletin. ELECTRICAL SYSTEM; UNKNOWN OR OTHER. The purpose of this CBR is to provide steps on how to correct a customer complaint of "Service Required" message for air filter replacement appears in the cluster. There may be no option in PTT or the cluster to reset the air filter service interval.
CBR 2596 2026082026-09-01. Service bulletin. ENGINE; ELECTRICAL SYSTEM. The purpose of this CBR is to provide steps on how to correct a customer complaint of a no crank/engine start condition.
CBR 2429 2026082026-09-01. Service bulletin. STRUCTURE:BODY; ELECTRICAL SYSTEM. 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.
TSB M-590-001 0720262026-08-03. Service bulletin. SERVICE BRAKES. TSB - Wheel Speed Sensor Fitting And Cable Clamping.
CBR 2585-3 0720262026-08-03. Service bulletin. ELECTRICAL SYSTEM. CBR - The purpose of this CBR is to provide support for fault codes C106718 and/or C106818.
CBR 2545-3 0720262026-08-03. Service bulletin. UNKNOWN OR OTHER; ELECTRICAL SYSTEM. CBR - The purpose of this CBR is to provide guidance on fault code U114688.
CBR-2591-1 2026062026-06-29. Service bulletin. ENGINE. The purpose of this CBR it to provide release notes for the recent Engine ECU software.
CBR-2590-2 2026062026-06-29. Service bulletin. 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-2588-2 2026062026-06-29. Service bulletin. ELECTRICAL SYSTEM. The purpose of this CBR is to provide aid in VMCU fault B1524-49 along with a Rain sensor which will not calibrate.
CBR-2587-2 2026062026-06-29. Service bulletin. ELECTRICAL SYSTEM. The purpose of this cbr is to provide steps on how to protect the alternator power cable connection from corrosion.
CBR-2586-1 2026062026-06-29. Service bulletin. ENGINE. The purpose of this CBR is to address issues of exhaust stack rotation on version 4 products.
CBR-2568-5 2026062026-06-29. Service bulletin. ELECTRICAL SYSTEM. Contact Workshop; Communication Lost With Ultracapacitor Message With Associated CCIOM DTC U100687 And A Startability Issue.
CBR-2496-16 2026062026-06-29. Service bulletin. ELECTRICAL SYSTEM. The purpose of this CBR is outline the interim software solution for PR(4) and AN(4).
CBR-2465-7 2026062026-06-29. Service bulletin. ELECTRICAL SYSTEM. The purpose of this CBR is to help diagnosis issues with the Proactive Engine Restart system and Hood Open popup message.
GDC26-02 2026052026-06-02. Service bulletin. ELECTRICAL SYSTEM; SEAT BELTS; AIR BAGS. Fault diagnostic information for Supplemental Restraint / Airbag Inflation System (SRS)
CBR 2587-1 2026052026-06-02. Service bulletin. ELECTRICAL SYSTEM. CBR to provide steps on how to protect the alternator power cable connection from corrosion.
CBR 2585-1 2026052026-06-02. Service bulletin. ELECTRICAL SYSTEM; WHEELS; SERVICE BRAKES. CBR to provide support for fault codes C106718 and/or C106818.

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