So... just trying to clear this up, and someone back me up if iv stepped too far. Fuel issues has mostly been eliminated as an issue do to the fact that the driver side functions just fine now. Cody eliminated the PCM as an issue. And all the injectors and solenoids ohmed out fine as well. So.... her issue must be somewhere between the IDM and the 42pin. Am I correct? That should simplify stuff greatly.

 

So, you think I need to replace IDM?
If so, are there instructions somewhere on how to do that please?
Thanks

 

Not necessarily. Get your codes read before you go about replacing a $300 part that you aren't sure is the issue. Once you get your codes read with a professional scan tool, you will know if your IDM is shot. Until then, it's only a shot in the dark. A shot in the right direction, but wait to pull the trigger until your sighted in on the actual cause of your issues

 

Okay...I will try and hunt one down. Thank you
Oh...If that is bad are their instructions on how to replace...I am defiantly not a mechanic, so I am looking for some good instruction. I hoping I can handle it

 

In an effort to explain a little bit about why it can't be the PCM (just to validate my earlier comments):

The PCM sends TWO signals to the IDM, a CID (Cylinder Identification) and FDCS (Fuel Delivery Command Signal). The signal we care about here is the CID. It is a high or low signal and switches states on cylinders 3 and 8. The signal stays high for the first set of four cylinders in the firing order and switches to low for the second set of four cylinders in the firing order. This is the only information that the IDM receives to "set" the firing order for the injectors.

If the firing order was such as each bank of cylinders fires alternately, then the CID signal to the IDM may be the culprit. However, the IDM sends a signal back to the PCM to verify that the signal was received....and if the CID never changes states, then the truck wouldn't run because the IDM would say, "WTF, mate?". In the real world, the cylinders fire in a series that puts two cylinders per bank sequentially so even if every other cylinder in the firing order wasn't firing, then there would be two on the left bank and two on the right bank that wouldn't be contributing, not an entire bank.

 

LOL...Okay...so I have read that like 5 times...Trying to make sure I understand. So, the truck DOES run, just like crap and at of course very reduced power. So, if I am reading it correctly The CID could not be it also because it fires every other...and we only have a passenger bank out. And IDM is not it because...its telling the PCM that it is all good?
Did I say that right?

 

Is there a way with my ohm meter to check between the 42 pin and IDM?
Or is there something specifically I should be looking for?
Thanks

 

I thought I was reading it to say that the IDM was the more plausible candidate between it and the PCM. Maybe I misunderstood something though.

 

More me that probly misunderstood.
Okay...Back to IDM....Still trying to find a local with a AE code reader.

 

check out this link that cutlass posted, this guys claimed it was a bad fuel pump that caused his passenger side to go down.

 

Thanks Chris..we checked the fuel pump too, before hubby left

 

I've been following this since the first post, but forget whether the wiring harness between the IDM and the 42 pin connected was VISUALLY checked for any insulation missing off of the wires. For that matter, how about between the 42 pin and passenger side Valve cover harness? I had a short that was only intermittent and everything would ohm out. Apparently it would take a bump or jiggle to make it short which then sent a message to the IDM shutting my whole drivers side bank down on some kind of safety mode. I ended up having a wire stripped inside the protective corrugated tubing.each wire needs to be carefully and individually inspected. You're not looking for a huge gash, just a flake missing here or there. Since I had that happen, I also had another short on one of my alternator wires, so for me, electrical is always the first place I look. While a short is frustrating to look for, at least it's a cheap fix. Just needs electrical tape. If this has already been tried, I apologize for duplicating previous advice. Good luck!

 

My how this thread has grown.

cleatus12r has not really eliminated anything yet. My friend Cody really knows his stuff, but some of that encyclopedic knowledge is difficult to translate into daily language. It is rumored I have a way with words, so I'll give it a try.

The PCM sends TWO signals to the IDM, a CID (Cylinder Identification) and FDCS (Fuel Delivery Command Signal). The signal we care about here is the CID. It is a high or low signal and switches states on cylinders 3 and 8.

The truck doesn't fire in the sequence 1, 2, 3, etc.... The firing order is on that picture of the 42-pin connector (albeit a mirror image of the firing sequence). 1, 2, 7, 3, 4, 5, 6, 8. The IDM get's a signal from the PCM that the first cylinder (#1) is next in line. In order to let the IDM know in advance, the PCM tells the IDM when #8 cylinder went by... as if to coach a T-ball batter - "Now!". The IDM gets the sequence started and carries on, but the one-armed IDM has no thumb. It can only count to four, so it needs another poke in the rib cage from the PCM when number 3 cylinder goes by (fourth one gone, fifth one ready - #4). This is how the PCM and IDM stay synchronized with each other.


Let's say the PCM is falling down on the job... just to suss this out. You would likely get a no-start, or you would get half of the cylinders (but not completely divided by left and right):

• If 1, 2, 7, and 3 were to fail... then it would be a safe assumption the PCM is up to no good. (this happened on the forum recently)
• If, 1, 5, 7, and 3 were to fail, then that would be an IDM or its electrical connections to the injectors.

You really need to know those codes, or to find out whether it's #5 or #2 that's missing with the others.

 

Not to cast stones, but you basically reiterated exactly what I said. If the entire right bank is not doing anything, then it CANNOT be the PCM. Even if it were possible that there was a PCM issue that would cause the listed symptoms, the truck wouldn't run because the IDM would not get the proper signal to "green light" a start.

The IDM does ONLY what it does because of the two signals I listed earlier. If either one doesn't happen (CID in this case), the truck doesn't run at all because the IDM won't do anything to electrically excite ANY of the injectors since it has no reference point to decide when to start the firing order. CID stuck low (low, off, 0, etc.): no start. CID stuck high (high, on, 1, etc.): no start. The chances of a coincidental sudden loss of the FDCS for JUST the odd number cylinders are about the same as never. In addition (not saying that Ford's diagnostic procedures are always spot on), I looked at the testing procedures for CID/FDCS just now and found that there are only TWO faults that are listed as "Replace PCM": If the CID doesn't toggle high during an output state test or if it doesn't toggle low during another output state test.

Hence, it cannot be a PCM issue. The truck runs and is not firing at all on the right bank.

I'll happily eat my words if it's not the case (but ONLY if the information we received from the original poster is correct in her symptom description). The information we have is that the entire right bank is dead. Just the right bank.

 

Here you go. I strongly suspect your problem lies somewhere here.