All PACCAR Fault Codes
187 PACCAR diesel fault codes. Click any code for causes, diagnostics, severity, and common fixes.
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-P1016 serious
Fuel Pressure Relief Valve Open
PACCAR-P1022 serious
Injector Cylinder 1 Circuit
PACCAR-P1023 serious
Injector Cylinder 2 Circuit
PACCAR-P1024 serious
Injector Cylinder 3 Circuit
PACCAR-P1025 serious
Injector Cylinder 4 Circuit
PACCAR-P1026 serious
Injector Cylinder 5 Circuit
PACCAR-P1027 serious
Injector Cylinder 6 Circuit
PACCAR-P1028 serious
Injector Power Supply Circuit
PACCAR-P1029 serious
CP3 High Pressure Pump Performance
PACCAR-P1031 serious
Turbocharger Actuator Circuit
PACCAR-P1032 serious
Turbocharger Actuator Position Sensor
PACCAR-P1033 serious
Turbocharger Overspeed
PACCAR-P1034 serious
Turbocharger Boost Pressure Too High
PACCAR-P1035 serious
Turbocharger Boost Pressure Too Low
PACCAR-P1041 serious
EGR Valve Position Sensor
PACCAR-P1042 serious
EGR Valve Actuator Circuit
PACCAR-P1043 serious
EGR Valve Stuck Open
PACCAR-P1044 serious
EGR Valve Stuck Closed
PACCAR-P1405 serious
DOC Efficiency Low
PACCAR-P1406 serious
DOC Face-Plugging Detected
PACCAR-P1407 serious
HC Doser Injector Circuit
PACCAR-P1408 serious
HC Doser Fuel Pressure Low
PACCAR-P1409 serious
HC Doser Shutoff Valve
PACCAR-P1414 serious
DPF Soot Load High
PACCAR-P1415 serious
DPF Soot Load Very High - Service Regen Required
PACCAR-P1416 serious
DPF Ash Load High
PACCAR-P1417 serious
DPF Regen Failed - Temperature Low
PACCAR-P1418 serious
DPF Regen Incomplete
PACCAR-P1420 serious
DPF Missing or Tampered
PACCAR-P1421 serious
DPF Face-Plugging Detected
PACCAR-P1423 serious
DPF Service Regen Timer Expired
PACCAR-P1429 serious
Exhaust Backpressure Too High
PACCAR-P1501 serious
DEF Tank Level Low
PACCAR-P1502 serious
DEF Tank Level Empty
PACCAR-P1506 serious
DEF Pump Module Motor Circuit
PACCAR-P1507 serious
DEF Pump Pressure Low
PACCAR-P1508 serious
DEF Pump Pressure High
PACCAR-P1509 serious
DEF Pump Performance - Cannot Build Pressure
PACCAR-P1511 serious
DEF Doser Valve Circuit
PACCAR-P1512 serious
DEF Doser Valve Stuck Open
PACCAR-P1513 serious
DEF Doser Valve Stuck Closed
PACCAR-P1516 serious
DEF Quality Fault - Concentration Out of Range
PACCAR-P1517 serious
DEF Incorrect Fluid Detected
PACCAR-P1519 serious
SCR Inlet NOx Sensor Performance
PACCAR-P1521 serious
SCR Outlet NOx Sensor Performance
PACCAR-P1522 serious
SCR Catalyst Efficiency Low
PACCAR-P1523 serious
SCR Catalyst Conversion Low
PACCAR-P1527 serious
SCR Catalyst Temperature Too High
PACCAR-P1529 serious
DEF Consumption Too High
PACCAR-P1530 serious
DEF Consumption Too Low
PACCAR-P1531 serious
DEF System Tampering Detected
PACCAR-P1600 serious
DPF Regen Too Frequent
PACCAR-P1607 serious
DPF Differential Pressure During Idle Excessive
PACCAR-P1609 serious
DPF Regen Temperature Overshoot
PACCAR-P1612 serious
CEM Aftertreatment Control Module Internal Fault
PACCAR-P1613 serious
CEM Communication Lost
PACCAR-P1615 serious
DPF Bypass Detected
PACCAR-P1703 serious
DEF Dosing Interrupted - Pressure Fault
PACCAR-P1704 serious
DEF Dosing Interrupted - Doser Fault
PACCAR-P1705 serious
DEF Metering Unit Performance
PACCAR-P1709 serious
Reductant Quality Poor - Verified
PACCAR-P1710 serious
NOx Conversion Efficiency Stage 1
PACCAR-P1711 serious
NOx Conversion Efficiency Stage 2
PACCAR-P2047 serious
Reductant Injector Circuit Open
PACCAR-P2048 serious
Reductant Injector Circuit Low
PACCAR-P2049 serious
Reductant Injector Circuit High
PACCAR-P204F serious
Reductant System Performance
PACCAR-P20E8 serious
Reductant Pressure Too Low
PACCAR-P229E serious
SCR NOx Catalyst Efficiency Below Threshold
PACCAR-U0100 serious
Lost Communication with ECM/PCM
PACCAR-U0101 serious
Lost Communication with TCM
PACCAR-U0121 serious
Lost Communication with ABS Module
PACCAR-P0091 moderate
Fuel Pressure Regulator 1 Control Circuit Low
PACCAR-P0101 moderate
MAF Circuit Range/Performance
PACCAR-P0102 moderate
MAF Sensor Circuit Low
PACCAR-P0103 moderate
MAF Sensor Circuit High
PACCAR-P0401 moderate
EGR Flow Insufficient
PACCAR-P0402 moderate
EGR Flow Excessive
PACCAR-P0500 moderate
Vehicle Speed Sensor Malfunction
PACCAR-P0562 moderate
System Voltage Low
PACCAR-P0563 moderate
System Voltage High
PACCAR-P0628 moderate
Fuel Pump Circuit Low
PACCAR-P0700 moderate
Transmission Control System Malfunction
PACCAR-P1005 moderate
Engine ECM Configuration Parameter Out of Range
PACCAR-P1006 moderate
VIN Not Programmed
PACCAR-P1007 moderate
Vehicle Speed Parameter Mismatch
PACCAR-P1017 moderate
Fuel Lift Pump Circuit Low
PACCAR-P1018 moderate
Fuel Lift Pump Circuit High
PACCAR-P1019 moderate
Fuel Temperature Sensor Circuit
PACCAR-P1020 moderate
Fuel Filter Restriction
PACCAR-P1021 moderate
Water in Fuel Detected
PACCAR-P1030 moderate
Fuel Pressure Low After Engine Run
PACCAR-P1036 moderate
Charge Air Cooler Outlet Temperature High
PACCAR-P1037 moderate
Intake Manifold Pressure Sensor Circuit
PACCAR-P1038 moderate
Intake Manifold Temperature Sensor Circuit
PACCAR-P1039 moderate
MAF Sensor Circuit
PACCAR-P1040 moderate
MAF Sensor Performance
PACCAR-P1045 moderate
EGR Cooler Efficiency Low
PACCAR-P1046 moderate
EGR Temperature Sensor Circuit
PACCAR-P1047 moderate
EGR Differential Pressure Sensor
PACCAR-P1048 moderate
Throttle Valve Position Sensor
PACCAR-P1049 moderate
Throttle Valve Actuator Circuit
PACCAR-P1050 moderate
Crankcase Breather Filter Restriction
PACCAR-P1400 moderate
DOC Inlet Temperature Sensor Circuit Low
PACCAR-P1401 moderate
DOC Inlet Temperature Sensor Circuit High
PACCAR-P1402 moderate
DOC Inlet Temperature Out of Range
PACCAR-P1403 moderate
DOC Outlet Temperature Sensor Circuit
PACCAR-P1404 moderate
DOC Outlet Temperature Performance
PACCAR-P1410 moderate
DPF Inlet Temperature Sensor Circuit
PACCAR-P1411 moderate
DPF Outlet Temperature Sensor Circuit
PACCAR-P1412 moderate
DPF Differential Pressure Sensor Circuit
PACCAR-P1413 moderate
DPF Differential Pressure Sensor Performance
PACCAR-P1419 moderate
DPF Regen Frequency Too High
PACCAR-P1424 moderate
Exhaust Temperature Sensor 1 Circuit
PACCAR-P1425 moderate
Exhaust Temperature Sensor 2 Circuit
PACCAR-P1426 moderate
Exhaust Temperature Sensor 3 Circuit
PACCAR-P1427 moderate
Exhaust Temperature Sensor 4 Circuit
PACCAR-P1428 moderate
Exhaust Backpressure Sensor Circuit
PACCAR-P1430 moderate
Exhaust Backpressure Valve Actuator
PACCAR-P1500 moderate
DEF Tank Level Sensor Circuit
PACCAR-P1503 moderate
DEF Tank Temperature Sensor Circuit
PACCAR-P1504 moderate
DEF Tank Heater Circuit
PACCAR-P1505 moderate
DEF Line Heater Circuit
PACCAR-P1510 moderate
DEF Pump Reversing Valve
PACCAR-P1514 moderate
DEF Doser Valve Temperature High
PACCAR-P1515 moderate
DEF Quality Sensor Circuit
PACCAR-P1518 moderate
SCR Inlet NOx Sensor Circuit
PACCAR-P1520 moderate
SCR Outlet NOx Sensor Circuit
PACCAR-P1524 moderate
SCR Inlet Temperature Sensor
PACCAR-P1525 moderate
SCR Outlet Temperature Sensor
PACCAR-P1526 moderate
SCR Catalyst Temperature Too Low for Dosing
PACCAR-P1528 moderate
SCR Ammonia Slip Detected
PACCAR-P1532 moderate
DEF Heater Relay Circuit
PACCAR-P1533 moderate
NOx Inlet Sensor Heater Circuit
PACCAR-P1534 moderate
NOx Outlet Sensor Heater Circuit
PACCAR-P1601 moderate
DPF Regen Too Infrequent
PACCAR-P1602 moderate
Parked Regen Requested
PACCAR-P1604 moderate
Parked Regen Aborted by System
PACCAR-P1605 moderate
DPF Inlet Pressure Sensor High
PACCAR-P1606 moderate
DPF Outlet Pressure Sensor High
PACCAR-P1608 moderate
DPF Thermal Management - Slow Warmup
PACCAR-P1610 moderate
Exhaust Throttle Valve Stuck
PACCAR-P1611 moderate
Exhaust Throttle Valve Feedback
PACCAR-P1614 moderate
DPF Zone Temperature Unstable
PACCAR-P1700 moderate
DEF Dosing Shut Off - SCR Too Cold
PACCAR-P1701 moderate
DEF Dosing Shut Off - SCR Too Hot
PACCAR-P1702 moderate
DEF Dosing Shut Off - Exhaust Flow Low
PACCAR-P1706 moderate
DEF Return Line Fault
PACCAR-P1707 moderate
DEF Supply Module Temperature High
PACCAR-P1708 moderate
DEF Supply Module Current Draw High
PACCAR-P2201 moderate
NOx Sensor Circuit Range/Performance (Bank 1 Sensor 1)
PACCAR-P2202 moderate
NOx Sensor Circuit Low Input
PACCAR-P2203 moderate
NOx Sensor Circuit High Input
PACCAR-P2209 moderate
NOx Sensor Heater Sense Circuit High
PACCAR-P229F moderate
NOx Sensor Bank 1 Sensor 2 Circuit
PACCAR-P2450 moderate
Evaporative Emission System Switching Valve
PACCAR-U0401 moderate
Invalid Data Received from ECM
PACCAR-P0128 minor
Coolant Temp Below Thermostat Regulating Temperature
PACCAR-P0380 minor
Glow Plug Control Circuit
PACCAR-P0615 minor
Starter Relay Circuit
PACCAR-P1010 minor
Engine Hours Counter Fault
PACCAR-P1422 minor
DPF Active Regen Inhibited - Conditions Not Met
PACCAR-P1603 minor
Parked Regen Aborted by Operator