DTC Hub Commercial Truck & Diesel Fault Codes
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All Engine Manufacturers

Browse 168 fault codes across 8 heavy-duty diesel engine brands.

🔧 The Engineering Behind Every Code — Every heavy-duty engine manufacturer approaches fault diagnostics differently. Cummins uses standard SAE J1939 codes plus an extensive proprietary library in INSITE. Detroit Diesel (DTNA) employs the Amplified Common Rail system with notoriously detailed fault codes. Volvo engineers its SCR system with a progressive fault cascade. PACCAR collaborates with Netherlands-based DAF Trucks for the MX-13 engine. International partnered with Germany's MAN for the parent-bore A26 engine design. Understanding the engineering philosophy behind each manufacturer helps you diagnose faults faster.
Caterpillar 5 codes • 1 series
J1939
Cummins 49 codes • 3 series
J1587, J1939
Detroit Diesel 44 codes • 2 series
J1939
International 14 codes • 1 series
J1587, J1939
Mack 5 codes • 1 series
J1939
PACCAR 25 codes • 2 series
J1587, J1939
Volvo 21 codes • 2 series
J1587, J1939
Generic 5 codes • 1 series
J1939