Jim Warman Posted April 18, 2006 Share Posted April 18, 2006 Subject is a late build 04... no start came from body shop... customer wanted to pick it up on Good Friday. Guess who had the misfortune of being there when the SM (aka "Princess"... she's a sweet young thing and I'm a dirty old man) arrived to "release" the truck. Background info... started for the shop foreman but batteries appeared "low" - so I'm told. He says he scanned codes (he has proven unreliable and I'm sick of carrying this deadbeat) and retrieved none.... possible, but I would have at least expected a P0603 from dead batteries. No start for customer... brought out the booster (Cat battery on a cart).... no start for me... checked the no start PIDs.... everything good (including RPM#) except FICM_SYNC = No. My Saturday to work, I squeeze in a few minutes to dig a little - bunch of codes that don't matter (yet) and CMDTC P2614 which I can clear but comes back after I crank the engine... check CMP_FM.... reads "no fault" but changes to "yes fault" when cranking.... and here's were it gets hazy. PPT "V" stops you about step 4 or 5 because of the no start and sends you back to section 4 of the PC/ED (which, to my beleagured old brain) sends me back to PPT V. OASIS was no help at all. I wound up using a combination of info gathered from a PowerStroke Central wizard and the FICM handbook (don't know if anyone else got it) that Ford supplied us. I unplugged the PCM and ohmed the CMP circuit at the PM plug. After this, I lost control of the subject (bigger fish to fry) and the sleazebaaa, err, shop foreman took over. I should mention that P2614 can also mean a problem with CMP_OUT from the PCM to the FICM... and this is what I wanted the SF to check.... he could find anything with the harness. Substitute a donor FICM... VROOOM. Put the original FICM back.... VROOOM. I am now, officially, waiting to hear back from one very disappointed customer when this concern resurfaces.... Moral of the story.... we can't blindly follow the PC/ED. Instead, we need badly to decide what a code really means (and that can be tough) and follw the diagnostics with an eye to being sure that we check what needs to be checked appropriately (understanding what a test step really wants - knowing that some test procedures in the PC/ED are inappropriate or misleading). If something smells bad, check all available documents. Sorry to get windy... I feel that anything we can do to expand our personal knowledge base makes us better (and more importantly) and more productive as techs.... I think the shop manuals are a real "minefield" and we need to pick our way carefully.... Quote Link to comment Share on other sites More sharing options...
Jwebb1981 Posted April 18, 2006 Share Posted April 18, 2006 When I went to school for 6.0, the teacher told us that 2 yrs ago he would have told us that the PC/ED was gold and we should follow its teaching. But todays PC/ED, he said that we have to be smarter than the person who wrote it. Quote Link to comment Share on other sites More sharing options...
Keith Browning Posted April 18, 2006 Share Posted April 18, 2006 The very idea that you need to understand how these engines work is the key. The PCED is fine for basic diagnostics. I agree that it can easily lead you in the wrong direction however I have learned THAT is usually the result of an improperly performed or misinterpreted test. Diesel engines have always been all about pressure and timing and the small window of time the fuel allows us to work with. While all of the advances in electronics have enabled engineers to build powerful and efficient engines the very same advances have created another entire set of problems. Until you can recognize both the basic theory of operation and the control systems that manipulate them, you will likely have difficulties in diagnosing many concerns. Recognizing the difference between the two and understanding their relationship is crucial. Eventually you will HAVE develop your own intuition. If you have an instructor that in some way gets you to think about what you are doing and why rather than just to obey the written instructions, then you have truly been educated. The book should not only guide you but it should also provoke thought. Quote Link to comment Share on other sites More sharing options...
Jim Warman Posted April 19, 2006 Author Share Posted April 19, 2006 There's been too many times someone has been hung ou to dry by the PC/ED.... Testing solenoids on the 4R100 comes to mind as a biggie... PC/ED has us testing for source voltage (using a DMM) at the solenoid body plug. This test is about as inappropriate as it gets (unless it has finally been changed in reprints) and has caused the replacement of solenoids unnecessarily... The best tool for this test is a small sealed beam headlamp... draws about 4 or 5 amps on low beam.... and allows us to check the load carrying capability of the circuit. There are other examples like this throughout the manuals making the need to think about each and every step of an unfamiliar PPT before, during and after we perform it. Quote Link to comment Share on other sites More sharing options...
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