Engine Operating Modes

[2007 5.9]

Does someone have or know what the different modes are and what they do and possibly what triggers them?

My 2350 is doing something that I can't understand what and why...

Tia

[GMPX]

I don't have a definitive list, but what number is it showing when you hit issues?

[2007 5.9]

Not really any issues but I can't understand what it's doing.

Starts in SCR1 until coolant gets to 180* them goes to Flow Control for about 1/2-sec then straight to normal mode.

Just trying to understand the process

[jk1956383]

Not really any issues but I can't understand what it's doing.

Starts in SCR1 until coolant gets to 180* them goes to Flow Control for about 1/2-sec then straight to normal mode.

Just trying to understand the process

Les,

What is happening, with the SCR1 mode, is the engine and aftertreatment need to get the SCR bricks above 250 DegC. Once above this threshold, the DEF will experience a reaction with the SCR Brick. This reaction will convert the DEF into ammonia. The release of ammonia will bond with the passing NOx molecules converting them into harmless compounds. So, from the time your truck is started until it reaches 180F Coolant Temp is probable about the same time it takes to get your SCR bricks to 250 DegC. Hope this helps!

Respectfully,

JK