scr warmup

[Rawze]

Actually, it is quite normal for the engine to jump back and fourth between its egr+ modes and one of its aftertreatment warm-up modes. It has to maintain 500-F degrees at the DPF/SCR, etc.. and it can only do this by jumping into a warm-up mode as those cans drop below about 450-F or so, and they cool off.

The idle alone in the EGR+ operating modes is not enough heat to keep the SCR/DPF temps under there up .. so it jumps as needed into a warm-up cycle to get them back where they need to be. It also, often, does this going down the roads every few mins, depending on weather.

If you want it to cycle less often, then an exhaust wrap to keep everything under there much warmer would help a lot.

As far as it cycling more than normal,.. it could be caused by many tings including an egr valve sticking open, leaky exhaust piping, one of the temp sensors under the truck not reading correctly, etc.