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
Only bulletins with component: Engine are shown. Show all
| TSB M257005 202608 | 2026-09-01. 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. |
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| CBR 2596 202608 | 2026-09-01. 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-2591-1 202606 | 2026-06-29. Service bulletin. ENGINE. The purpose of this CBR it to provide release notes for the recent Engine ECU software. |
| CBR-2586-1 202606 | 2026-06-29. Service bulletin. ENGINE. The purpose of this CBR is to address issues of exhaust stack rotation on version 4 products. |
| CBR 2465-6 202605 | 2026-06-02. Service bulletin. ELECTRICAL SYSTEM; ENGINE. CBR to diagnosis issues with the Proactive Engine Restart system and Hood Open message. |
| S4757 022026 | 2026-03-03. Service campaign. ENGINE. SC - Certain model AN(4)’s and PR’s could experience DEF leaks or crystallization due to the installation of incorrect fasteners for the Urea Dosage Valve. |
| SC S4742 202601 | 2026-02-03. Service campaign. ENGINE. CBR MCO/VECI Label Reprint. |
| CBR 2522-5 202601 | 2026-02-03. Service bulletin. ENGINE. CBR - Frequent Parked Regeneration Requests - Models PR (4), AN (4). |
| CBR 2535 202512 | 2026-01-05. Service bulletin. ENGINE. The purpose of this CBR is to address reports of regeneration failure when ambient temperature is below 30F. |
| CBR 2526-4 202511 | 2025-12-03. Service bulletin. ELECTRICAL SYSTEM; ENGINE. CBR - Parking Heater Inoperative - PR(4) - AN (4). |
| CBR 2525-2 202511 | 2025-12-03. Service bulletin. ENGINE. CBR - Exhaust Leak or Noise – Turbo Compound (TC) Bolt Inspection and Repair - PR (4). |
| CBR 2408-15 202511 | 2025-12-03. Service bulletin. ENGINE; ELECTRICAL SYSTEM. CBR - Air Production Modulator (APM) DTC C10129B - High/Excessive Flow PR(4). |
| CBR 2408 092025 | 2025-10-01. Service bulletin. UNKNOWN OR OTHER; ENGINE. This document provides guidance for addressing the APM DTC C10129B fault," High/Excessive Flow" This fault was introduced by a previous APM software package and requires specific containment actions. |
| GDC25-010 092025 | 2025-09-29. Service bulletin. ENGINE. Engine Coolant Level Low - Elevated Coolant & Oil Temperature |
| GDC25-009 092025 | 2025-09-29. Service bulletin. ENGINE. Engine Oil Pressure Too Low |
| GDC25-008 092025 | 2025-09-29. Service bulletin. ENGINE. Engine Coolant Over Temperature |
| GDC25-006 092025 | 2025-09-29. Service bulletin. ENGINE. Engine Oil Over Temperature |
| GDC25-005 092025 | 2025-09-29. Service bulletin. ENGINE. Exhaust Gas Temperature Sensor Circuit Short to Battery or Open |
| GDC25-001 092025 | 2025-09-29. Service bulletin. ENGINE. Particulate Filter Restriction - Soot Accumulation Bank 1 |
| CBR 2330 072025 | 2025-08-04. 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 2107-21 202505 | 2025-06-02. Service bulletin. FUEL/PROPULSION SYSTEM; ENGINE. Mack DEF Level (UQLS) Sensor Troubleshooting Guide - US17+OBD16 Emissions and Newer |
| CBR 2463-3 202504 | 2025-05-05. Service bulletin. ENGINE. CBR - The purpose of this CBR is to assist in determining source(s) of suspect abnormal turbocharger noise. |
| CBR-561 202503 | 2025-04-02. Service bulletin. ENGINE. If oil dilution is suspected refer to the applicable CBR solution below: ∙ CBR-659Mack Chassis - Oil Diluted With Fuel; Fuel In Oil, Diagnostic Information - All Emissions, All Model Years |
| S4342-202502 | 2025-03-03. 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-997 202411 | 2024-12-02. 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.