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Cummins Diesel Engine Fault Codes

Browse 11 diagnostic trouble codes across 2 engine series. Protocols: J1587, J1939.

🔴 4 STOP ENGINE 🟡 5 Check Next Stop 🟠 2 Check Soon

Cummins Inc. has been the undisputed leader in heavy-duty diesel engines in North America for over 100 years. The ISX15 engine — now X15 — powers approximately 40% of all Class 8 trucks on American highways. Cummins fault codes use the standard SAE J1939 protocol, but Cummins also maintains an extensive library of proprietary fault codes accessible through Cummins INSITE. Our database covers both public SPN/FMI codes and Cummins-specific interpretations.

ISX15 Engine Series — 8 fault codes

SPN 1569 FMI 31
Engine Protection Torque Derate
🔴 STOP ENGINE
Component: Engine Control Module (ECM) • J1939
SPN 102 FMI 18
Intake Manifold Pressure critically low
🔴 STOP ENGINE
Component: Turbocharger / Charge Air System • J1939
SPN 111 FMI 18
Engine Coolant Level critically low
🔴 STOP ENGINE
Component: Coolant Level Sensor / Cooling System • J1939
SPN 639 FMI 9
J1939 CAN Bus Communication Loss
🔴 STOP ENGINE
Component: Engine Control Module / CAN Bus • J1939
SPN 1322 FMI 31
Misfire Detected on Cylinder 6
🟡 CHECK AT NEXT STOP
Component: Cylinder 6 Injector / Valve Train • J1939
MID 128 SID 1 FMI 5
Injector Cylinder 1 Circuit
🟡 CHECK AT NEXT STOP
Component: Fuel Injector #1 Solenoid Circuit • J1587
SPN 191 FMI 16
Transmission Output Shaft Speed
🟡 CHECK AT NEXT STOP
Component: Transmission Output Speed Sensor (TOSS) • J1939
MID 128 PID 102 FMI 3
Boost Pressure Sensor
🟠 CHECK SOON
Component: Intake Manifold Pressure Sensor • J1587

X15 Engine Series — 3 fault codes

SPN 4364 FMI 18
SCR Inducement Active
🟡 CHECK AT NEXT STOP
Component: Selective Catalytic Reduction (SCR) System • J1939
SPN 4334 FMI 7
DEF Dosing Valve Mechanical Fault
🟡 CHECK AT NEXT STOP
Component: DEF Dosing Valve (DMU) • J1939
SPN 3031 FMI 9
DEF Quality Abnormal
🟠 CHECK SOON
Component: DEF Quality Sensor / DEF Tank • J1939