Ok here it goes. This only happens when I am towing my 35ft toy box 5th wheel.
And generally only up long pulls up hill. I will get a check engine light. It will go away after about the 3rd restart after I stop pulling my trailer. I ran the codes and it shows P0404 which is EGR. Then yesterday my tow / haul light started flashing. But no trouble code stored. The light would stop flashing, then start again. As soon as I stopped towing and turned the tuck back on, no more light.

Any ideas?

 

It's possible you have codes stored that your reader isn't capable of reading. Regardless, it sounds like you also have a bad EGR valve. Try cleaning it and having your codes read by something different.

 

Also possible that it's the over 15* spread turning the light on...then off again.

 

His profile says 2003 MY but being in Az. he may very well have a California flashed truck which turns the CEL on for EGR codes, IIRC. No CEL for ECT/EOT's on those, as I'm sure you already know.

 

IIRC, it's 2005 and up that the new flash will dtc on the eot/eoc delta.

 

My bad. Haven't changed my profile. I have an '06 F250 King Ranch.

Any how, I cleaned the EGR and I still get the light.

Trans light flash still occuring. Trans temp gauge goes to zero as well.

 

Mofire,
Same with my 06 F350 DRW, Threw p0404, during long uphill pull. Never had the Tow light flashing though. Ford replaced oil cooler due to EOT vs ECT more than 15 degree spread. I ripped out the EGR cooler and Valve. Haven't had a problem since. Pulled the I-17 north bound from PHX to Flag in August with 28' toy hauler 8K+. No more problem. I'm in Yuma if you're close by, and need help.
928-503-2194

 

I'll be in Vegas for the rest of the week. I'll drop you a line Saturday or Sunday.

Thanks