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.
187 fault codes documented· 2 engine variants · J1939 SPN/FMI · 2010 - present
Most Common PACCAR Fault Codes
Showing 24 of 187 PACCAR codes, sorted by severity. Each links to causes, diagnostics, common fixes, and repair cost estimates.
PACCAR-P1001 critical
Engine ECM Internal Fault
PACCAR-P1002 critical
Engine ECM Memory Checksum Error
PACCAR-P1712 critical
NOx Conversion Efficiency Stage 3 - Shutdown Imminent
PACCAR-P0087 serious
Fuel Rail Pressure Too Low
PACCAR-P0088 serious
Fuel Rail Pressure Too High
PACCAR-P0191 serious
Fuel Rail Pressure Sensor Circuit Range/Performance
PACCAR-P0234 serious
Turbocharger Overboost
PACCAR-P0299 serious
Turbocharger Underboost
PACCAR-P0300 serious
Random Cylinder Misfire
PACCAR-P0335 serious
Crankshaft Position Sensor Circuit
PACCAR-P0340 serious
Camshaft Position Sensor Circuit
PACCAR-P0341 serious
Camshaft Position Sensor Performance
PACCAR-P0420 serious
Catalyst System Efficiency Below Threshold Bank 1
PACCAR-P0607 serious
Control Module Performance
PACCAR-P060A serious
Internal Control Module Monitoring Processor Performance
PACCAR-P1003 serious
Engine ECM Power Supply Fault
PACCAR-P1004 serious
Engine ECM Software Calibration Incompatibility
PACCAR-P1008 serious
CAN J1939 Bus Off
PACCAR-P1009 serious
ECU Ground Fault
PACCAR-P1011 serious
Fuel Rail Pressure Sensor Circuit Low
PACCAR-P1012 serious
Fuel Rail Pressure Sensor Circuit High
PACCAR-P1013 serious
Fuel Rail Pressure Control - Pressure Too Low
PACCAR-P1014 serious
Fuel Rail Pressure Control - Pressure Too High
PACCAR-P1015 serious
Fuel Metering Unit Circuit
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