SPN 3490 FMI 7 Purge AIR ACTUATOR

[srsttrans]

Hello everyone. KW T680 Cummins ISX CM2350 getting code
Fault code 3225 PID
SPN 3490
FMI 7
AFT Purge Air Actuator mechanical system not responding
Replaced air actuator, put brand new - did not work, also replaced all air fittings so there is no air leak along the way to actuator. Replaced air dryer filter. Still code coming up, stays for few days and goes away randomly.
Any ideas what else need to check?

[Waterloo]

I looked up that code and it directed me to the SCR Doser, have you serviced the SCR system lately? There is a filter cartridge in the system too that needs to be changed out periodically...

Those SCR dosers can crystalize up and do need to be changed out periodically, along with the exhaust fuel doser. Have you ever given this truck an EGR Tuneup?

Is the truck regenerating properly, do you have Insite and an Inline reader? If not, you need one NOW.

[srsttrans]

(08-16-2020 )Waterloo Wrote:  I looked up that code and it directed me to the SCR Doser, have you serviced the SCR system lately? There is a filter cartridge in the system too that needs to be changed out periodically...

Those SCR dosers can crystalize up and do need to be changed out periodically, along with the exhaust fuel doser. Have you ever given this truck an EGR Tuneup?

Is the truck regenerating properly, do you have Insite and an Inline reader? If not, you need one NOW.

Yes I did service EGR lately. Replaced EGR cooler since it was leaking, cleaned all pipes and intake manifold. Boost pressure sensor. But never got to Def doser. Its good to know this fault related to def doser. It was actually giving me a fault about outlet nox sensor, but it was fmi 9 - reading incorrect. And Nox sensor fault may come up ad go away in a day. Thx for replay. Will service it asap

[srsttrans]

(08-16-2020 )Waterloo Wrote:  I looked up that code and it directed me to the SCR Doser, have you serviced the SCR system lately? There is a filter cartridge in the system too that needs to be changed out periodically...

Those SCR dosers can crystalize up and do need to be changed out periodically, along with the exhaust fuel doser. Have you ever given this truck an EGR Tuneup?

Is the truck regenerating properly, do you have Insite and an Inline reader? If not, you need one NOW.

By any chance do you know if def doser from cummins will work with Volvo D13 engine? That volvo def dosers are expensive and look same as cummins

[Waterloo]

No clue about the DEF doser and different manufacturers. I am sure they are proprietary.

[srsttrans]

(08-16-2020 )Waterloo Wrote:  No clue about the DEF doser and different manufacturers. I am sure they are proprietary.

One more question
I did force regen last time with Insite and one time stationary when fault was inactive. Seems everything went through. What parameters should I look up when start proceed with regen? What other test would you recommend to do?

[JimT]

My research found that the def dosers are nearly universal, pretty much all made by Bosch. They are not OEM component, they are specific to your Engine (ESN) and aftertreatment system, but in reality I think all the OEMs use the same Bosch part. Pull the DEF doser valve off and compare the manufactuerers part numbers, try a google search. I found some cheap ones on amazon, but the one I tried leaked from day one. If you're keeping the system intact I would just spend the ~$400ish and get a genuine one that probably passed quality assurance.

Also replace the DEF filter. It's located on the underside of the DEF pump which is located under the DEF tank. 3 bolts hold the bottom cover on. take on bolt out and slightly loosen the other 2 and the plate will swing down like a door. New filter comes with a plastic tool to remove the old filter. Make sure new filter is push ALL THE WAY UP! It will pop in to place. Otherwise the lower cap will not screw on all the way and you will leak DEF everywhere.

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OK, now to the PIA part, the purge air actuator. I had a problem with mine for almost 2 years. Never did figure out the cause. There is a detailed set of troubleshooting steps to follow in quickserve and the location of the actuator is a pain to get to, especially on my Pete since everything seems to run through that one spot. Mine worked most of the time. Even when it threw a code it didn't inhibit regens like insite/quickserve says it should. Leads me to think the problem was maybe a faulty wire or maybe a small air leak somewhere. Just enough to trip the code briefly then go back to functioning normally.

I'm not aware of the DPF purge air actuator being related in any way to the DEF system, unless that code is for a different system.