The Cummins 3712 Code, often accompanied by the 3714 code, can be a frustrating issue for diesel truck owners. This code indicates “Aftertreatment SCR Operator Inducement – Data Valid but Above Normal Operational Range – Most Severe Level.” Essentially, the engine’s aftertreatment system, specifically the Selective Catalytic Reduction (SCR) system, is detecting abnormal operating parameters. This often results in derate mode, limiting engine power to protect the system from further damage. This article will discuss troubleshooting steps and solutions for resolving these codes, specifically focusing on the Cummins ISB 6.7L engine.
Understanding Cummins 3712 and 3714 Codes
The Cummins 3712 code signifies a serious issue within the SCR system, while the accompanying 3714 code (“Engine Protection Torque Derate – Condition Exists”) indicates the resulting engine derate. Both codes often persist even after the initial problem triggering them has been resolved. This can be due to the codes latching in the engine control module (ECM).
According to documented conditions for clearing these fault codes, they should become inactive once all other active fault codes are addressed. The ECM should then turn off the corresponding warning lamps (red STOP ENGINE lamp for 3712 and amber CHECK ENGINE lamp for 3714) after a successful diagnostic run. However, as many technicians have experienced, this isn’t always the case.
Troubleshooting Cummins 3712
The first step in addressing a Cummins 3712 code is to diagnose and fix any underlying issues. This may involve:
- Checking for other fault codes: Use a diagnostic scanner to identify any other active codes that might be contributing to the 3712. Address these codes first.
- Inspecting the particulate sensor: A faulty particulate sensor can trigger various aftertreatment issues. If the sensor is bad, replace it.
- Performing a regeneration and SCR test: This test helps assess the functionality of the aftertreatment system and identify potential problems. Ensure temperatures are within the normal range and the system passes all tests.
Resolving Persistent 3712 and 3714 Codes
If the 3712 and 3714 codes persist after addressing all other issues, a software issue within the ECM might be the culprit. In these cases, reflashing the ECM with the latest calibration often proves effective. This involves updating the ECM’s software to the most recent version.
Experience with a 2017 Cummins ISB 6.7L engine exhibiting persistent 3712 and 3714 codes, despite a successful particulate sensor replacement and passing regen/SCR tests, demonstrated the effectiveness of ECM reflashing. After the reflash, the codes cleared, and the engine resumed normal operation. Even reinstalling the same calibration can sometimes resolve the issue.
Conclusion
The Cummins 3712 code indicates a significant issue within the SCR system, often leading to engine derate. While addressing underlying problems is crucial, persistent codes may require reflashing the ECM. This solution has proven effective in resolving stubborn 3712 and 3714 codes in various instances, particularly on the 2017 ISB 6.7L engine. If you encounter these codes, following the outlined troubleshooting steps and considering ECM reflashing can help restore your engine’s performance.
