SPN 3490 FMI 7 Purge AIR ACTUATOR

[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.