Cummins fault code 3325
DOC Intake Temperature Swapped: out of calibration
What it means
Cummins' description: Aftertreatment 1 Diesel Oxidation Catalyst Intake Temperature Swapped - Out of Calibration.
SPN 4765 is Aftertreatment Diesel Oxidation Catalyst Intake Temperature. FMI 13 means the component or software calibration doesn't match what the ECM expects.
The DOC (diesel oxidation catalyst) sits ahead of the DPF and burns fuel and hydrocarbons to heat the exhaust for regeneration. Some engines have a separate aftertreatment fuel doser (the 7th injector) that sprays fuel into the exhaust for regen.
What the lamp means
An amber (yellow) warning lamp means the engine can usually keep running, but the fault should be repaired soon, ideally the same day.
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 temperature sensor code that appears once and clears, with regens finishing normally.
Schedule a repair
Regens failing or taking much longer than usual, along with DOC or doser codes. Book diagnosis before the DPF loads up.
Stop and get help
Raw fuel smell, smoke out of the stack, or a stop lamp. Don't run it. Unburned fuel in the exhaust is a fire risk and can destroy the DPF.
Common causes
The sensor reading itself is out of range or the condition is real, so look at the system:
- Aftertreatment fuel injector clogged or coked up
- DOC face-plugged with soot or oil
- DOC catalyst worn out or contaminated
- Fuel or air leak at the doser assembly
- Exhaust leak ahead of the DOC
What you can check before calling
- Look for soot or fuel residue at the aftertreatment fuel doser and lines
- Check for exhaust leaks between the turbo and the DOC
- Note whether regens are completing or being interrupted
Clearing the code without fixing the cause usually brings it right back, and on emissions systems it can restart derate timers. For the bigger picture, read our guide: DPF regeneration explained: passive, active and forced.
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: Cummins Tier 4 Fault Codes. Always confirm with Cummins service information (QuickServe) for your engine serial number.
Same SPN, other failure types
- 3251 SPN 4765 FMI 16
DOC Intake Temperature: reading above normal (moderately severe) - 3313 SPN 4765 FMI 4
DOC Intake Temperature Sensor Circuit: circuit voltage low / shorted low - 3314 SPN 4765 FMI 3
DOC Intake Temperature Sensor Circuit: circuit voltage high / shorted high - 3315 SPN 4765 FMI 2
DOC Intake Temperature: erratic or intermittent signal - 6539 SPN 4765 FMI 2
DOC Intake Temperature: erratic or intermittent signal
Related DOC and aftertreatment fuel doser codes
- 3249 SPN 4810 FMI 15
Warm Up DOC Outlet Temperature: reading above normal (least severe) - 3247 SPN 4809 FMI 16
Warm Up DOC Intake Temperature: reading above normal (moderately severe) - 3225 SPN 3490 FMI 7
Purge Air Actuator: not responding / out of adjustment - 3224 SPN 3490 FMI 3
Purge Air Actuator Circuit: circuit voltage high / shorted high - 3223 SPN 3490 FMI 4
Purge Air Actuator Circuit: circuit voltage low / shorted low - 3169 SPN 4810 FMI 16
Warm Up DOC Outlet Temperature: reading above normal (moderately 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 3325 mean?
Cummins fault code 3325 is J1939 SPN 4765 FMI 13: Aftertreatment 1 Diesel Oxidation Catalyst Intake Temperature Swapped - Out of Calibration. In plain terms: doc intake temperature swapped: out of calibration.
Can I keep driving with Cummins code 3325?
Usually for a short time, if the engine runs normally and no other warnings are on. Get it diagnosed soon, because many amber codes lead to a derate if ignored. Look at the green, yellow and red examples on this page to judge your situation.
What is the SPN and FMI for Cummins code 3325?
SPN 4765 identifies the part or system (Aftertreatment Diesel Oxidation Catalyst Intake Temperature). FMI 13 describes the type of failure: out of calibration.
What usually causes Cummins code 3325?
The most common causes are: aftertreatment fuel injector clogged or coked up; dOC face-plugged with soot or oil; dOC catalyst worn out or contaminated.
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.