PACCAR MX Fault Codes
PACCAR Inc. manufactures its own MX-11 and MX-13 engines for Kenworth and Peterbilt Class 8 trucks, as well as DAF trucks in Europe. Both engines share compacted graphite iron blocks and modern SCR / DPF aftertreatment. Fault codes are reported as J1939 SPN/FMI pairs and PACCAR-proprietary fault codes visible through the dash display or Davie4 scan tool.
2 engine variants · J1939 SPN/FMI · 2010 - present
PACCAR Engine Versions
| Engine | Years | Applications | Notes |
|---|---|---|---|
| MX-11 | 2014-present | Kenworth T680/T880, Peterbilt 567/579 | 10.8L inline-6 weight-sensitive applications; lighter than MX-13 for regional haul and vocational. |
| MX-13 | 2010-present | Kenworth T680/T880, Peterbilt 567/579, DAF XF | 12.9L inline-6. Most common PACCAR engine in Class 8 on-highway. Compacted graphite iron block. |
Common PACCAR MX Issues
- Aftertreatment faults: DEF doser, SCR catalyst efficiency, DPF differential pressure sensor
- EGR cooler failures and EGR valve sticking -- similar to other HD diesel platforms
- Turbocharger VGT actuator failures and boost pressure sensor drift
- Coolant leaks from the thermostat housing and water pump
- NOx sensor (inlet and outlet) failures -- frequent replacement interval on high-mileage trucks
Most Common Fault Codes
PACCAR MX fault code data is being populated. Pages will include SPN/FMI descriptions, probable causes, diagnostic tests, and common fixes sourced from PACCAR Davie4 service literature and field experience.