Code Details
| Display code | SPN 412 FMI 0 |
|---|---|
| SPN | 412 |
| FMI | 0 |
| OEM code | None listed |
| Manufacturer | Cummins |
| System | Engine �?EGR system |
| Component | EGR cooler / EGR temperature sensor |
| Source address | Unknown or not applicable |
| Severity | medium |
| Review status | source backed |
| Source confidence | medium |
| Last reviewed | 2026-06-11 |
Plain-English Meaning
The EGR cooler on the ISX15 and X15 uses engine coolant to cool the hot recirculated exhaust gases before they re-enter the intake. When the EGR gas temperature after the cooler is too high, the cooler is not removing enough heat. This can be caused by restricted coolant flow through the cooler, a bypassed or damaged cooler, or a faulty temperature sensor. Excessively hot EGR gases entering the intake affect combustion quality and can damage intake components.
SPN 412 is Engine EGR Temperature in J1939. FMI 0 indicates the temperature is above the normal operating range. On Cummins CM2350 ISX15/X15, the EGR temperature sensor is located after the EGR cooler to monitor cooler performance. A high reading indicates the cooler is undershooting its thermal target. Insite monitors EGR inlet and outlet temperatures, coolant temperature, and EGR cooler bypass valve position to characterize the cooler's thermal performance.
Common Symptoms
- Check engine lamp active
- Possible higher intake air temperatures from hot EGR gas contribution
- Potential coolant loss if the EGR cooler is developing an internal leak alongside the high-temperature condition
Possible Causes
Possible causes may include the items below. The list is not a parts diagnosis.
- Restricted coolant flow through the EGR cooler from scaling or blockage
- EGR cooler bypass valve partially or fully open, routing EGR around the cooler
- EGR cooler structural failure reducing heat transfer area
- EGR temperature sensor drift reading high
First Checks
- Connect Cummins Insite and monitor EGR temperature before and after the cooler, plus coolant temperature
- Check the EGR cooler bypass valve position in Insite �?a stuck-open bypass valve would cause uncooled EGR to bypass the cooler
- Check coolant flow to the EGR cooler �?a partially blocked coolant supply line reduces cooler effectiveness
- Inspect for coolant loss that might indicate an EGR cooler internal failure alongside the high-temperature fault
Can I Keep Driving?
The engine is typically still driveable, but high EGR temperatures affect combustion quality and may accelerate intake system wear. If coolant loss is also occurring, address the fault urgently.
Related Codes
Related Lookup Pages
Sources
- Cummins INSITE Service Tool — Public Reference Documentation Cummins Inc. · oem · accessed 2026-06-11 · confidence medium
Source: Cummins Inc., Cummins INSITE Service Tool — Public Reference Documentation. This page paraphrases factual fields only and is not a substitute for the original document.
Open source - QuickServe Online Cummins Inc. · oem · accessed 2026-05-05 · confidence medium
Source: Cummins Inc., QuickServe Online. This page paraphrases factual fields only and is not a substitute for the original document.
Open source - SAE J1939 Standards Collection SAE International · official · accessed 2026-05-05 · confidence medium
Source: SAE International, SAE J1939 Standards Collection. This page paraphrases factual fields only and is not a substitute for the original document.
Open source
FAQ
How often do EGR coolers fail on the Cummins ISX15 or X15?
EGR cooler failures �?from internal coolant leaks, scaling blockage, or bypass valve sticking �?are a documented issue across many heavy-duty diesel platforms including the ISX15 and X15. Failure rates increase at higher mileages and with aggressive duty cycles. Regular coolant condition monitoring (SCA concentration and pH) helps extend EGR cooler service life by preventing internal corrosion and scaling.
Can the EGR cooler be cleaned on the ISX15 rather than replaced?
EGR coolers with scaling deposits from degraded coolant can sometimes be cleaned using chemical flushing procedures. However, a cooler with structural cracks, internal tube failure, or severely restricted passages typically requires replacement. Insite thermal performance data can help determine whether cleaning is likely to restore adequate cooling performance.
What coolant specification should be used in a Cummins ISX15 or X15 to protect the EGR cooler?
Cummins recommends using coolant meeting the Cummins ES Compleat OAT specification, which provides extended organic acid inhibitor protection compatible with the aluminum and copper components in the EGR cooler. Maintaining the correct SCA (supplemental coolant additive) concentration and pH per the service schedule is important for EGR cooler longevity.