Cummins Fault Code 3714 indicates an engine protection torque derate condition. This code often appears alongside code 3712, signifying an issue with the aftertreatment SCR system. While replacing faulty sensors, such as the particulate sensor, may resolve underlying problems, codes 3712 and 3714 might persist even after repairs. This article discusses the conditions for clearing these codes and a potential solution involving reflashing the engine control module (ECM).
Understanding Cummins Fault Codes 3712 and 3714
Code 3712 points to an abnormality in the SCR system, indicating data exceeding the normal operational range. Code 3714, coupled with 3712, signifies that the engine has entered a derate mode to protect itself from potential damage. Both codes are classified as “Most Severe Level,” necessitating immediate attention.
The diagnostic process for both codes involves addressing all other active fault codes first. The official documentation states that once these underlying issues are resolved, codes 3712 and 3714 should automatically clear. The ECM is programmed to turn off the red STOP ENGINE lamp (for 3712) and the amber CHECK ENGINE lamp (for 3714) after a successful diagnostic run.
Troubleshooting Persistent 3712 and 3714 Codes
Even after repairs and successful regeneration and SCR tests, codes 3712 and 3714 may remain. This scenario often occurs because the codes become “latched” in the ECM’s memory, potentially due to a software glitch. In such cases, standard diagnostic procedures may not be sufficient to clear the codes.
One effective solution is to reflash the ECM with the latest calibration. This process updates the ECM’s software, effectively overwriting the latched codes and restoring normal operation. This method has proven successful in resolving persistent 3712 and 3714 codes, even when no new calibration updates are available. Reinstalling the same calibration can sometimes be enough to clear the error.
Case Study: 2017 ISB 6.7L
A case study involving a 2017 Cummins ISB 6.7L engine exemplifies this scenario. After replacing a faulty particulate sensor and performing a successful regen and SCR test, codes 3712 and 3714 persisted. Reflashing the ECM with the latest calibration successfully cleared the codes and resolved the derate condition.
Conclusion
Cummins fault codes 3712 and 3714 indicate serious issues requiring immediate attention. While addressing underlying mechanical problems is crucial, reflashing the ECM is often necessary to clear persistent codes and restore normal engine function. This solution effectively addresses potential software issues that may prevent the codes from clearing through standard diagnostic procedures.
