Cat 299d2 scr issue

[PrestonB]

I have a 2018 299d2 vin-fd201875

The code that I’m having a issue with that pops up about 45 min give or take after running is 4364-1 aftertreatment #1 scr catalyst conversion efficiency low-most severe(3)

I don’t have cat eat. But I can read a little bit of live data off of my snap-on computer. When I was looking around on the computer I did notice a couple things.

1st- my aft 1 dpf differential pressure is always showing 0psi.

2nd- aft 1 exhaust temp 2 preliminary fmi shows (it switches back and forth between 3 things)
1-bad intelligent device or component
2- current below normal or open circuit
3-voltage below normal, or shorted to low source

If I cut the machine off after the code pops up and let it sit for a few minutes the code will go away. Until it’s ran hard for a little while and then the code will pop back up.

I have noticed that the def gauge hasn’t moved in quite some time. So I’m not sure if it’s even spraying into the system. I do hear the def pump running for a few minutes after cutting the machine off. So I’m assuming it’s working.

Any help with this situation would be greatly appreciated.

 

[Nige]

The attached may be of some assistance.

 

[pittsburgh cat man]

I’m thinking I would try a little of this

 

[PrestonB]

Back working on this machine. Still having the same issue. Throwing one single code and going into limp mode. Anybody have a diagram or picture of where the AFT 1 temperature sensor 2 is located on this machine?

 

[Nige]

Is this any help.?

 

[Nige]

Do you have an electrical schematic.? That would help relate Part Numbers machine to locations.

 

[PrestonB]

Got some new info. On my snapon pro-link ultra I can see some live data. The one I’m watching is labeled AFT 1 temperature sensor 2 and

With key on engine off it will show a message of data valid but below normal operational range- most severe.

With the machine running at idle the message will switch between- current below normal or open circuit, currant above normal or grounded circuit, mechanical system not adjusting or out of adjustment, and abnormal frequency or pulse width or period

if I idle the machine up I get new messages. I get root cause not know, abnormal rate of charge. bad intelligent device or component, special instructions, and out of cal.

Before I dig into that sensor I want to be sure I’m on the right path.

 

[PrestonB]

Do you have an electrical schematic.? That would help relate Part Numbers machine to locations.

No I do not

 

[Nige]

No I do not

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