Brad Clayton Posted January 24, 2013 Share Posted January 24, 2013 2011 F-250 mil on (DEF related codes)This 6.7L powered vehicle came in with the check engine light on and no noticeable drivability issues.IDS pulled a few codes shown here. I usually like to follow the code that is currently exhibiting a fault. In this case it is P208C. I always review how the system works and look at the EVTM to see what is involved before diving in. An easy trick for looking up codes is to use “control + F” a find box will pop up and then type in the code you want to find. The code will appear on the screen and you won’t have to scroll through all the codes. This feature works well for SLTS also when looking for overlapping labor ops. The code leads to pinpoint test RG which will basically check the reductant pump, circuits, and PCM. I am going to step back from the pinpoint test for a bit and look at the EVTM.The setup is pretty basic and you have power, ground, and control. It’s time to do a visual inspection of the truck. The spare tire is dropped out of the way to get better access to the DEF pump. The pump and wiring were inspected for damage from road debris and chaffing of any kind, everything looked ok. On a side note, the pump can be changed without dropping the tank. I wanted see what was happening since the problem was occurring at this time so I employed the dosing measurement test. I like to use it for powering the DEF pump because the screen is nice and easy to see and it’s a quick tool to use. As seen here, the pump builds “0” pressure. There is obviously a problem with the system. I grabbed my meter and checked for power and ground to the pump. I chose not to load test the wires at the moment because I am just trying to get some basic numbers at this time.A dosing measurement test was reran to power the pump and this is the reading observed. It seems very low and I am not sure what it should be. It’s time to consult the OBD2 theory and operation manual to see how this pump is activated. This description states that code P208C will set if the control voltage is below 3.5 volts. I am at half that so here is the problem. Looking at the EVTM again, there is one connector C139 between the PCM and DEF pump.I disconnected the connector to rule it out before moving on and noticed some corrosion. Further inspection and these offending corroded pins were removed and replaced from the connector on both the female and male sides. The system was reassembled and brought back on-line and this was the voltage reading while dosing…. …..and I now have plenty of PSI in the DEF plumbing. This was a bit of a tricky vehicle that took a little thinking outside the norm to keep from replacing unnecessary parts. The vehicle was back on the road and fixed right the first time and the customer was “completely” satisfied. Quote Link to comment Share on other sites More sharing options...
lmorris Posted January 24, 2013 Share Posted January 24, 2013 After mindlessly replacing a few pumps myself, I have now started removing and throughly inspecting that harness. Found a few corroded connector pins and wires since. Quote Link to comment Share on other sites More sharing options...
Bruce Amacker Posted January 24, 2013 Share Posted January 24, 2013 Is there a root cause to this like salt intrusion? Or DEF creeping up the wires? Harness pulled too tight, allowing moisture to get by the seal? Just thinking.... Quote Link to comment Share on other sites More sharing options...
Brad Clayton Posted January 24, 2013 Author Share Posted January 24, 2013 Salt and road brine. That connector sits right in front of the def tank and behind the fuel tank. Crap just sits on top of there. Quote Link to comment Share on other sites More sharing options...
lmorris Posted January 24, 2013 Share Posted January 24, 2013 Salt and road brine. That connector sits right in front of the def tank and behind the fuel tank. Crap just sits on top of there. We have taken to instructing customers to wash off the top of the tank on a regular basis now. Quote Link to comment Share on other sites More sharing options...
Brad Clayton Posted January 24, 2013 Author Share Posted January 24, 2013 Had one come in one day after a rough day during mud season, and I had to wash the top of the tank for a couple of minutes just to start to see the def pump! Quote Link to comment Share on other sites More sharing options...
Matt Saunoras Posted January 25, 2013 Share Posted January 25, 2013 Brad I just had a the external trans connector on a torqshift 6 do the same thing to me. Ending up having to replace both the external and internal harness. Water intrusion and a bunch of corroded terminals on a vehicle with 20k miles. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.