I often wondered why the actual sensor value (voltage, frequency, etc.) was always reported along with the corresponding quantity (pressure, temperature, etc.). Thank you so much for that explanation, it makes perfect sense now.

 

And thanks Greg (Shakeandbake) for your detailed assessment about what's actually happening with our trucks. I learn more every day about the extremely complicated nuances these engines put forth to we uneducated and under educated psuedo "mechanics" trying to keep our vehicles operating in a somewhat cost effective way.
Thank you very much!

 

Greg thanks for explaining how the pcm handles info from the sensors. Learn something new everyday. Thanks

I was wanting part #'s so I could write them down in my service manual. Thanks
I guess I should have looked on Clay's or Bob's website. I am trying to get all the part #'s for things I might need all in one place. Hopefully at some point I'll be able to just carry spare parts.

 

If you can get your hands on a PC/ED manual it will go a long way to filling in the blanks between the wealth of info here on FTE and what you can observe with AE. Really helped me out a ton....

I once had the pleasure of chatting with one of the engineers who designed the control systems on these engines and he told a story about how they all jumped around for joy when they finally got the engine started on a test stand. Some thought the system would work perfectly and others were doubtful the engine would start at all.

Turns out the system fundamentals are quite sound and ended up becoming legendary in the light diesel community. The more I learn about these systems, the more I come to respect the complete package that allows these trucks to continue to operate even when one or more systems have failed or fallen offline.

Tip: The PCM is just one of several 'modules' on board your vehicle. It does a lot but still relies on other modules to operate the truck, (IDM, ABS and AIC (if equipped) for example). All these modules communicate with each other and make decisions based on input from the various system sensors. The vehicle as a whole is controlled by a committee of modules, (which was quite ground breaking at the time). The actual 'work' comes from relays and solenoids that are controlled by one or more of the modules.

So, sensors take measurements and report that info to one of the power train modules. The modules in turn share that information between themselves.
Regulators/Solenoids/Relays do the work based on what the modules are requesting.

It's possible for a sensor to fail and the engine might still run perfectly fine. Losing a regulator or solenoid usually produces a symptom of some sort.

Hope this helps.


I just realized the part numbers I listed are International numbers. If you want Ford numbers then try:

IPR F81Z-9C968-AB
ICP F6TZ-9F838-A

I am not super positive, but it appears the suffix (A, AA, AB, BB etc) refer to part design revisions. So, a second revision ICP sensor might have a AA where the original design was just a single A. I am still trying to verify if this is actually true or not......at the moment, it's just a theory of mine based on some observations of various part numbers for different things.