Service bulletins for the 2018 Mack Terrapro
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.
234 on file from NHTSA, as of 2026-10-19.
About P1121 on the 2018 Mack Terrapro: what the code means, and the bulletins and recalls about the same components.
By type
By component
By trouble code
Only bulletins with trouble code: P1121 are shown. Show all
| K86900043 | 2019-07-15. Service bulletin. ENGINE AND ENGINE COOLING. Exhaust Gas Recirculation (EGR) System - Fault Codes SPN 412 FMI 0,2,5; Diagnostic Trouble Codes (DTC) P040A, P040B, P1121 - Temperature Sensor Inspection |
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| K52535491 | 2019-05-20. Service bulletin. ENGINE AND ENGINE COOLING:EXHAUST SYSTEM:EMISSION CONTROL:GAS RECIRCULATION VALVE (EGR VALVE). Diagnostic / Troubleshooting Procedures For EGR System Components; Diagnostic Trouble Codes (DTC) P0401-00, P0402-00, P04DD-00, P1121-00, P1121-98 Or SPN 2659 FMI 16, SPN 2659 FMI 18, SPN 412 FMI 0, SPN 412 FMI 15 - US10, US10+OBD13, US14+OBD*, US17+OBD* With A Variable Geometry Turbocharger (VGT) |
The summaries are NHTSA's. Each bulletin's page links NHTSA's copy of the manufacturer's document.