Mechanic's Explanation Doesn't Make Any Sense (Demands te)

[Vancity]

Hi guys,

Been dealing with a local mechanic here and he said a couple things that don't make sense to me.

1. I got a truck demandated, the service engine light stays on constantly (been months) and says 25% derated. Mechanic said he needs to update the ecm and will do it later on and it's fine if the light stays on and there is no issues with the truck.

2. Another truck that was demandated had an ECM go bad (truck would shutoff and power on randomly). Mechanic said if I bought a new ECM from kenworth, he would have to charge me for a full demandate again. So I ended up going with a used ECM he already had that was already demandated. Isn't it possible to just copy the cummins calibration file from the bad ECM that is demandated to the brand new one?

3. I have a 2013 Cummins CM2250. Truck is mandated. Whenever the truck is running idle the turbo is making a sound. I would describe it as the turbo is oscillating. Turbo gauge doesn't move. Mechanic said it's not an issue, but my other isx don't do it so I feel like it's a problem.

I have a Cummins Insite but only use it to check faults and do manual regens.

Could anyone please advise whether what the mechanic is saying is true. I have a gut feeling that he is not giving me the story straight.