Cummins fault code 5391
DOC Temperature Sensor Module: abnormal update rate
What it means
Cummins' description: Aftertreatment Diesel Oxidation Catalyst Temperature Sensor Module - Abnormal Update Rate.
SPN 6882 is Aftertreatment Diesel Oxidation Catalyst Temperature Sensor Module. 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.
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
Listed by Cummins for: QSB 6.7 (DOC+ SCR), QSL 9 (DOC+ SCR), QSB 4.5. 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
- 5392 SPN 6882 FMI 12
DOC Temperature Sensor Module: bad device or component - 5393 SPN 6882 FMI 3
DOC Temperature Sensor Module: circuit voltage high / shorted high - 5394 SPN 6882 FMI 4
DOC Temperature Sensor Module: circuit voltage low / shorted low - 5395 SPN 6882 FMI 11
DOC Temperature Sensor Module: root cause not known - 5396 SPN 6882 FMI 16
DOC Temperature Sensor Module: reading above normal (moderately severe)
Related DOC and aftertreatment fuel doser codes
- 5389 SPN 4766 FMI 15
DOC Outlet Gas Temperature: reading above normal (least severe) - 5388 SPN 4766 FMI 16
DOC Outlet Gas Temperature: reading above normal (moderately severe) - 5387 SPN 4766 FMI 0
DOC Outlet Gas Temperature: reading above normal (most severe) - 5386 SPN 4766 FMI 2
DOC Outlet Gas Temperature: erratic or intermittent signal - 5617 SPN 524286 FMI 31
DOC System- Special Instruction: condition exists - 4534 SPN 4766 FMI 4
DOC Outlet Gas Temperature Sensor Circuit: circuit voltage low / shorted low
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 5391 mean?
Cummins fault code 5391 is J1939 SPN 6882 FMI 9: Aftertreatment Diesel Oxidation Catalyst Temperature Sensor Module - Abnormal Update Rate. In plain terms: doc temperature sensor module: abnormal update rate.
Can I keep driving with Cummins code 5391?
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 5391?
SPN 6882 identifies the part or system (Aftertreatment Diesel Oxidation Catalyst Temperature Sensor Module). FMI 9 describes the type of failure: abnormal update rate.
What usually causes Cummins code 5391?
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.