Cummins fault code855 · Spark Plug Prognostic Cylinder 5 (A3)
Spark Plug Prognostic Cylinder 5 (A3) - Data Valid But Above Normal Operating Range - Least Severe Level
855 Cummins fault code as shown in INSITE / CaltermSPN1298 · Engine Spark Plug #5 VoltageFMI15 Data valid but above normal operating range - least severe levelOBD codenone (J1939 only)LampMaintenance lampCummins textSpark Plug Prognostic Cylinder 5 (A3) - Data Valid But Above Normal Operating Range - Least Severe LevelFailure modeData Valid But Above Normal Operating Range - Least Severe LevelWhat Cummins code 855 means
The reading for Spark Plug Prognostic Cylinder 5 (A3) is believed to be correct, but it has gone slightly above the normal operating range. This is the least severe of the three "above range" levels (FMI 15, 16 and 0); it is usually an early warning rather than an immediate problem.
It drives the MAINTENANCE lamp rather than the warning or stop lamp: the ECM is asking for service attention, not an immediate stop.
On a generic J1939 scan tool, or on the dash of a Freightliner, Kenworth, Peterbilt, International or Volvo chassis, the same fault is shown as SPN 1298 FMI 15 rather than as Cummins code 855. Cummins INSITE and Calterm show the Cummins number, the SPN / FMI pair and the lamp together.
Custom DTC delete, up to 30 codes, $150. Full DPF / EGR / SCR delete with all related codes and derates, $500. Upload your Calterm .xcal, tick the services, pay with PayPal, and the finished file comes back by email and WhatsApp.
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Find your ECFG →Other Cummins codes on SPN 1298 Engine Spark Plug #5 Voltage
9 other fault codes share this SPN; each one is a different failure mode (FMI) of the same component.
Related Cummins fault codes
J1939 failure mode identifiers (FMI)
FMI 15 is highlighted. The FMI is the second half of every J1939 fault and tells you how the component failed; the SPN tells you which component.
| FMI | Meaning (SAE J1939-73) |
|---|---|
| 0 | Data valid but above normal operational range - most severe level |
| 1 | Data valid but below normal operational range - most severe level |
| 2 | Data erratic, intermittent or incorrect |
| 3 | Voltage above normal, or shorted to high source |
| 4 | Voltage below normal, or shorted to low source |
| 5 | Current below normal or open circuit |
| 6 | Current above normal or grounded circuit |
| 7 | Mechanical system not responding or out of adjustment |
| 8 | Abnormal frequency, pulse width or period |
| 9 | Abnormal update rate |
| 10 | Abnormal rate of change |
| 11 | Root cause not known |
| 12 | Bad intelligent device or component |
| 13 | Out of calibration |
| 14 | Special instructions |
| 15 | Data valid but above normal operating range - least severe level |
| 16 | Data valid but above normal operating range - moderately severe level |
| 17 | Data valid but below normal operating range - least severe level |
| 18 | Data valid but below normal operating range - moderately severe level |
| 19 | Received network data in error |
| 20 | Data drifted high |
| 21 | Data drifted low |
| 22 | Reserved for SAE assignment |
| 23 | Reserved for SAE assignment |
| 24 | Reserved for SAE assignment |
| 25 | Reserved for SAE assignment |
| 26 | Reserved for SAE assignment |
| 27 | Reserved for SAE assignment |
| 28 | Reserved for SAE assignment |
| 29 | Reserved for SAE assignment |
| 30 | Reserved for SAE assignment |
| 31 | Condition exists |
Questions about code 855
What does Cummins fault code 855 mean?
Cummins 855 is "Spark Plug Prognostic Cylinder 5 (A3) - Data Valid But Above Normal Operating Range - Least Severe Level". It maps to SPN 1298 FMI 15. The reading for Spark Plug Prognostic Cylinder 5 (A3) is believed to be correct, but it has gone slightly above the normal operating range. This is the least severe of the three "above range" levels (FMI 15, 16 and 0); it is usually an early warning rather
Which lamp does fault code 855 turn on?
Maintenance lamp: It drives the MAINTENANCE lamp rather than the warning or stop lamp: the ECM is asking for service attention, not an immediate stop.
How do I clear or permanently delete Cummins code 855?
An active code goes inactive on its own once the condition is gone; the inactive record stays in the ECM fault history until it is cleared with Cummins INSITE (or a J1939 tool that supports the DM3 / DM11 clear). If the code keeps coming back because the part is gone, disconnected or not worth repairing, the lasting fix is to disable fault 855 in the calibration: upload your .xcal to the ECFG Superstore file service, custom DTC delete from $150 (up to 30 codes), full DPF / EGR / SCR delete $500, and flash the returned file with Calterm or INSITE.
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