You wanted me to come all the way down there to get that information but Ken was able get it from you for $5
LLY Ficm
- Thread starter mplecha
- Start date
You wanted me to come all the way down there to get that information but Ken was able get it from you for $5
I was just playing with you!I am getting it sorted out. Although It is no wonder I can dress my self if I can't scale it correctly... Don't say I didn't warn you earlier in this thread.
It's only been like 12 years since I messed with the scope stuff...
But I was serious about possibly being able to get an X-ray of the board in the future.
Hopefully he gets some good white wire capture to compare. Best I can assume without seeing the whole data file for both Engine Speed wires yet, one versions of our FICM uses a crank trigger signal, while other uses a Tach pulse style signal. But I distinctly recall there being a difference between the blue and white wire signals on my LLY when wiring up that tach adapter.. Maybe it's pulses per rev, but bet we find it.
I'd be interested in that X ray for sure. Would go a long way towards repairing the few LLY FICM's we have left.
I am getting it sorted out. Although It is no wonder I can dress my self if I can't scale it correctly... Don't say I didn't warn you earlier in this thread.
It's only been like 12 years since I messed with the scope stuff...
But I was serious about possibly being able to get an X-ray of the board in the future.
I was looking at the schematics you posted up yesterday, and caught a couple things interesting.
On the Engine Signal pin, both LB7 and LLY say 2x of 57x in the pin description. Ideas?
Second thing I caught, is in picture two circled in Orange.. Thinking someone used Copy / Paste when laying out this diagram, and nobody caught this small discrepancy. Or GM has some wild firing order going on...
Last thought, I secured an LB7 to test on over the weekend. Also think I found a full LB7 harness, FICM, and ECM to build a bench test rig out of. Plus some other LLY FICM junk we can test with.
Really looking for a LLY ECM and harness to layout on the bench with my little crank emulator rig.
Also my GM guru brought up a good point we haven't touched on yet. He says the crank sensor on a LB7 was 12v while LLY is 5v sensor? So we need to keep that in consideration when comparing signals on all these lines between the two..
On the Engine Signal pin, both LB7 and LLY say 2x of 57x in the pin description. Ideas?
Second thing I caught, is in picture two circled in Orange.. Thinking someone used Copy / Paste when laying out this diagram, and nobody caught this small discrepancy. Or GM has some wild firing order going on...
Last thought, I secured an LB7 to test on over the weekend. Also think I found a full LB7 harness, FICM, and ECM to build a bench test rig out of. Plus some other LLY FICM junk we can test with.
Really looking for a LLY ECM and harness to layout on the bench with my little crank emulator rig.
Also my GM guru brought up a good point we haven't touched on yet. He says the crank sensor on a LB7 was 12v while LLY is 5v sensor? So we need to keep that in consideration when comparing signals on all these lines between the two..
On the 2x or 57x there was a little discussion about that in the other LLY FICM thread. Starts about post 157. (Maybe merge the threads?). Do t think we figured it out but my guess was the speed
I too noticed the weird labeling of the injector lines. Didn't spend too much time on it as I figured it must have been a mistake or like you said, copy and paste
The 12 to 5 volt is easy to fix with a set of voltage divider resistors. But good to know so we don't burn something up plugging 12 volts into something that is designed for 5
I'm not really an expert, but I don't think there's any real 'intelligence' in the ficm... If you look on TIS,
don't believe it's listed, suggesting it's a dumb module that takes x input and spits out y output. Essentially.Sent from my Pixel 7 using Tapatalk
That's my take on it tooI'm not really an expert, but I don't think there's any real 'intelligence' in the ficm... If you look on TIS,don't believe it's listed, suggesting it's a dumb module that takes x input and spits out y output. Essentially.
Sent from my Pixel 7 using Tapatalk
I'm with ya on the dumb module. Which is a good thing. Ask my GM buddy, who said never recalled seeing any FICM updates in all his years working on em. Yet we know they have data wires, but for what or who do they talk..I'm not really an expert, but I don't think there's any real 'intelligence' in the ficm... If you look on TIS,
Sent from my Pixel 7 using Tapatalk
I'm 99% certain they won't run without the Engine Speed wire. So still betting the key difference is in that signal.. Seems I have mail with some scope logs, so guess I should go review them now.
Definitely can attest to neither generation will run without the engine speed signal.
@TheBac
Jason says We need some merging with this thread. https://www.duramaxdiesels.com/forum/threads/lly-ficm.89101/
I can see it getting messy. The overlap of replies could make them look like people are replying to the wrong discussion. Posting stuff that doesn't look relevant, etc