SCR again...a new code

[pgls651]

Cummins ISX 15 cm2350. Hit the derate with a code I haven't seen before. 1682- Aftertreatment Diesel Exhaust Fluid Dosing Unit Input lines-Condition Exists.

Ive recently replaced the Doser. There is leaking/crystallization around the base of the pump module but not from any lines. And the truck has been sitting for a while. Any ideas that this could be a DEF pump failure? Ive never had the issue. I've got Insite, though not sure about tests I can run on diagnosing.

[Bengy88]

I would personally fix what’s causing the crystallization and pull the lines and possibly doser and clean them with water, put them back on and perform my scr test and see what happens if it has been sitting a while

[Rawze]

also check the screens at the DEF pump.

quickseerv says...

Possible causes of this fault code include:

Low aftertreatment diesel exhaust fluid level in the diesel exhaust fluid tank

Either high or low diesel exhaust fluid pressure.

The line heaters are not successfully thawing the frozen diesel exhaust fluid

The diesel exhaust fluid pressure line between the dosing unit and dosing valve is kinked, broken, or disconnected

The diesel exhaust fluid suction line between the diesel exhaust fluid tank and the dosing unit is kinked, broken, or disconnected

Malfunctioning diesel exhaust fluid dosing unit

The diesel exhaust fluid suction and return lines between the dosing unit and diesel exhaust fluid tank are reversed

Debris from the diesel exhaust fluid tank. If debris is found in the diesel exhaust fluid tank, clean the diesel exhaust fluid tank thoroughly and fill with certified diesel exhaust fluid.

[JimT]

(08-02-2023 )pgls651 Wrote:  Cummins ISX 15 cm2350. Hit the derate with a code I haven't seen before. 1682- Aftertreatment Diesel Exhaust Fluid Dosing Unit Input lines-Condition Exists.

Ive recently replaced the Doser. There is leaking/crystallization around the base of the pump module but not from any lines. And the truck has been sitting for a while. Any ideas that this could be a DEF pump failure? Ive never had the issue. I've got Insite, though not sure about tests I can run on diagnosing.

just a guess, but pull the def lines and make sure they aren't clogged up, like Bengy88 said. Did you look up that code on Quickserv and follow the troubleshooting steps?

also, wouldn't hurt to check the wiring for the DEF pump and such. Dunno about the 2350, but my 2250 has relays and fuses for that inside my battery box and I think it's controlled by the DCU which is also (on my truck) located near the battery box under the cab. Those DEF lines, and the tank too, all have heater elements that work to keep the DEF from freezing.