Problem with my Superduty.

[kydale]

2011 Ford F-350 dually. 67k miles bought new. When I get in truck and go somewhere the "service engine indicator " is on. And stays on. Next time stays off. Dealership says fault code P204B Ran point test suspect Def pump. Pump test Ok. They suggested replacement of pump, 1200 bucks. But they aren't positive that is the problem.

Anyone else had anything similar?

[Passin_Thru]

Usually you should start with the main connectors between the Computer Control Module and other things. Pull them off and look for corrosion, put Non conductive grease on them (lots of it)After 6 years everything can corrode. Yes, I read the guys answer but I am a mechanic.

[Grit_dog]

MountainAirMan wrote:
P204B
Possible causes:
Slow responding reductant pressure sensor
Damaged reductant pressure sensor

There you have it, OP. Thanks to this guy for looking it up and not speculating like the rest of us.
Question is, is that sensor able to be replaced or is it built in to the system and requires replacing the whole pump or ......

[leggy]

My engine light in my 12 F-350 has been on for almost 2 years. Cause DEF heater. According to local dealer, the heater is not covered by emissions warranty. I have not had any issues with regen in the whole time it's been on. So, they said maybe it's a sensor or something and they would be happy to start throwing parts at it if I wanted to. One of these days I'll just delete it, I know a guy who is very good.

[Lynnmor]

Just so you know, a DEF pump can be bought for $268.66 at autonationfordwhitebearlake.com

[kydale]

The batteries aren't that old. The dealership told to drive it also. That I wouldn't hurt anything.

[rexlion]

MountainAirMan wrote:
P204B
Possible causes:
Slow responding reductant pressure sensor
Damaged reductant pressure sensor

A sensor problem was my guess, too, since it's running fine otherwise. The sensor won't hurt anything... just drive it.

[RSD559]

I thought emissions warranties were mileage based. Not mileage and time. Maybe I'm thinking the old days. Well, not the real old days before emission standards.

[Hannibal]

Check your grounds and wiring harnesses too for any chaffed spots from engine vibrations. Intermittent problems like that are often voltage or wiring related.

[Hannibal]

How old are your batteries? If they're questionable and need to be replaced anyhow... In my career as an elevator mechanic working on microprocessor controlled equipment, low voltage from a regulator, power supply or battery can cause multiple problems and fault codes. Just a long shot in the dark with a limb in the way.

[kydale]

I'm going to drive it for awhile and see what happens. Right now the indicator is off. Then I may look for another diesel shop to take it to.

[newman_fulltime]

def heater might be dirty if comes on cool moist days its seeing it not burning off so throws a code

[MountainAirMan]

P204B
Possible causes:
Slow responding reductant pressure sensor
Damaged reductant pressure sensor

[Grit_dog]

Oh and go to a Powerstroke forum and read up/ ask the question. Going to be a lot more pertinent info you can digest.

Idk what the best one is now. Thedieselstop I think?

[Grit_dog]

kydale wrote:
Doesn't seem to be using any more Def than normal. Truck runs like it always has. Service engine lite once on stays on till I shut engine off. Restart sometime it's on and sometimes not.

Could be some intermittent condition or an issue with a non essential part (when it's warm) like Kaytegs thing with the tank heater.
Have you cleared the code and see how long it stays off?
Just seat of the pants speaking if it's using def like it always does and is also regen ing like normal, it may be tough to diagnose until something actually fails without throwing parts at it.

If it were me, id consider riding it out until a physical symptom presents itself.