Cummins fault code 479
Exhaust Port Temperature Bank Imbalance: abnormal update rate
What it means
Cummins' description: Exhaust Port Temperature Bank Imbalance.
SPN 1318 is Exhaust Port Temperature Bank Imbalance. FMI 9 means data the ECM expects to receive over the network stopped arriving or arrived too slowly. Usually a communication, power, or module problem.
Large Cummins engines can have an exhaust temperature sensor at each cylinder's exhaust port. Comparing them lets the ECM spot a cylinder that is running hot, cold, or not firing.
What the lamp means
This code normally doesn't turn on a dash lamp. It's logged in the ECM for a technician to see, and often explains another active code.
Green, yellow, red: three ways this can look
The same code can be a quick fix or a reason to shut down. Match your situation to the closest example.
Keep an eye on it
A single exhaust temperature sensor code with the engine running smoothly.
Schedule a repair
The code keeps returning or several cylinders show imbalance. Book diagnosis. It can hide a real cylinder problem.
Stop and get help
Exhaust temperature imbalance with rough running, smoke or a stop lamp. Shut it down. A cylinder running very hot can burn a piston or valve.
Common causes
The sensor reading itself is out of range or the condition is real, so look at the system:
- Real imbalance from a weak injector or misfire in that cylinder
- Exhaust leak at the manifold
- Valve problem in that cylinder
What you can check before calling
- Look for heat-damaged wiring along the exhaust manifold
- Note any rough running or smoke
Clearing the code without fixing the cause usually brings it right back, and on emissions systems it can restart derate timers.
Engines and sources
Cummins uses the same fault code numbers across its electronic engines, including on-highway models like the ISB/B6.7, ISL/L9 and ISX/X15, though not every code applies to every engine or software level. Source: Diagnostic Fault Codes for Cummins Engines. Always confirm with Cummins service information (QuickServe) for your engine serial number.
Related Exhaust temperature sensors codes
- 641 SPN 1137 FMI 0
High #1 LB Cylinder Exhaust Temperature: reading above normal (most severe) - 642 SPN 1138 FMI 0
High #2 LB Cylinder Exhaust Temperature: reading above normal (most severe) - 643 SPN 1139 FMI 0
High #3 LB Cylinder Exhaust Temperature: reading above normal (most severe) - 644 SPN 1140 FMI 0
High #4 LB Cylinder Exhaust Temperature: reading above normal (most severe) - 645 SPN 1141 FMI 0
High #5 LB Cylinder Exhaust Temperature: reading above normal (most severe) - 646 SPN 1142 FMI 0
High #6 LB Cylinder Exhaust Temperature: reading above normal (most severe)
Look up another code
Cummins fault code (like 1922), J1939 SPN and FMI (like SPN 3251 FMI 0), or an OBD-II code (like P0420).
Questions
What does Cummins fault code 479 mean?
Cummins fault code 479 is J1939 SPN 1318 FMI 9: Exhaust Port Temperature Bank Imbalance. In plain terms: exhaust port temperature bank imbalance: abnormal update rate.
Can I keep driving with Cummins code 479?
Usually, yes. This code doesn't normally turn on a lamp by itself, but check for other active codes that might be more serious. Look at the green, yellow and red examples on this page to judge your situation.
What is the SPN and FMI for Cummins code 479?
SPN 1318 identifies the part or system (Exhaust Port Temperature Bank Imbalance). FMI 9 describes the type of failure: abnormal update rate.
What usually causes Cummins code 479?
The most common causes are: real imbalance from a weak injector or misfire in that cylinder; exhaust leak at the manifold; valve problem in that cylinder.
Diesel down in the Midlands?
We work on Cummins-powered pickups, vans and medium-duty trucks across Lexington, Columbia and the Midlands, on site at your yard or roadside.