CM870 Smoking Issues

[Submariner]

So a quick update as the saga continues with this engine.... It started dumping smoke badly at idle again today. I pulled over to a parking lot, disconnected the air hose to the turbo. The actuator moved smoothly through the full range and the smoking increased in the “big turbo” position. On a whim, I disconnected the intake air temp sensor on the manifold, engine fan kicked on immediately and with in seconds the smoke cleared and ran perfect. Installed another new temp sensor, fan disengaged and immediately started pouring smoke out the stacks. Unhooked the sensor, fan came back on and smoke cleared, idled perfectly. According to KW, the new ECM has the latest Cummins software version and is correct for the CPL. Do these engines when they loose a input like intake air temp, default to a “safe” fuel map?