2016 Ford F250 Cooling Fan
I got this truck last week with the complaint that sometimes the fan sounds like it is running at full speed. I never could duplicate the complaint, but I had a code for the AC pressure transducer circuit Low. Not sure the exact code don't have access to my work order right now. Checked for ref voltage and checked for solid ground and had both. Watched Pressure PID and Volts for the transducer it never got over 175 psi or 2 volts. Inspected the harness found a place that was starting to rub through on a bracket. Called the customer and told him that I could not duplicate but that I wanted to split the harness and see if I was shorting out. Did not find any exposed wire so I re-taped and added extra and repositioned the harness as much as I could. Told him I did not find anything and thought it had to be the transducer so I got the Ok to replace it. Test drove and watched the fan RPM and Engine RPM as well as the pressure transducer. The fan RPM matched the engine RPM for about One or Two Minutes the was running quite a bit slower as I would expect. It came back this week and it is worse. Now I can duplicate. The Fan RPM exceeds the engine RPM until it get to nearly operating temp. This time I have no codes and Fan reads OK. This guy has already replaced the fan clutch with an aftermarket one and says it did the same thing. He has had the truck for 6 months and says it was this way when he bought it. I don't want to through another part at it until I'm sure. My Question is shouldn't the fan run slower the the engine until it is hot or commanded by the PCM for a reason. I saved the data from the first time I test drove it after the repair and the data from today and it is definitely different. I would think that I would have a code if the fan was not doing what it should? Any Ideas would be appreciated. I don't think i have had this problem on this 6.2 before and I'm not sure if it's not just a strategy for the fan.
The fan is going into to default as commanded by the PCM. There is data missing for the PCM or EATC system. There should be a way to read the fan command and the AC transducers. You need to follow the flow charts for the code, once you can access your notes. Evaluate the system with a set of gauges and determine what is going wrong. There is a TSB as I recall for the ambient temp sensor and…
Using Snap On Verus cannot find a command PID to see what the PCM is commanding I would love to have that Info. I think I will scope it this morning and see what the actual duty cycle is, but unless I know what the PCM wants It will not help much. Seems like IDS has a PID for command.
What is the duty cycle for the fan when problem is occuring? It sounds like an issue with the fan clutch to me, my previous experience with Ford electrovis fan clutches has been that they won't lock up even if the pcm is commanding it until the clutch reaches a certain temperature.
Jimmy I would would suggest looking at PPT HV in the PC/ED. I think HV 13 and HV 14 might have some helpful info. Can you also post your scan data?
I will If I can figure out how to post when I get to the shop. Thanks for the tip about PC/ED I forget to look at the symptom chart with out a code. I still have a question about the 2 min time for the fan to disengage. It seems like it takes a little longer than that, but after it dose it works normal until it cools down again. Dose it take that long for the fluid in the fan to work?
I have had two of these where the fan was running at high speed at times. In both cases, it was repaired by changing out the thermostats. Engine was warming up too slowly for the PCMs liking. Once the fans came on, they wouldn't stop until the key was shut off…in both cases, there were no code, nor any indication that anything was wrong. AM fans are always junk.