03 LB7 crank no start. No coms with ficm

bogema

03 CC/SB LB7, 02 XCLB 8.1, 85 K5 6.2/6.5 S366
Aug 22, 2023
14
4
3
Michigan
Yeah the mega fuse test good and only .1v drop across it. Is the pcm/ecm All in one(housing) looks like the diagram, and my tcm on the radiator. I think I'd still be missing wires, and connectorsare incorrect color too? I'll look at the connectors and such in the morning again cause now I'm all confused and I'll have to draw it all back out again on paper.
 

2004LB7

Well-known member
Dec 15, 2010
6,982
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Norcal
Yes. ECM is one single unit. Located lower down clower to the power steering reservoir. The TCM is up high on the radiator. FICM opposite side by alternator
 
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bogema

03 CC/SB LB7, 02 XCLB 8.1, 85 K5 6.2/6.5 S366
Aug 22, 2023
14
4
3
Michigan
So I check her all over again that same group of wires you highlighted and that I made a list of and a few extras, qnd got the same results just a little higher voltages from being on the chatger. So i started to look backwards. Traced the first wire back to under the fuse panel J2-E6 for the edu relay control pin 76 on the ecu gry/blk wire had corroded off of the terminal in the jumper connector. Cleaned and replaced the wire in a new connector and she fired right up! So clearly that's a wire you want to use for a kill switch! Lol. Thank you all for your help and knowledge!! Now to replacing wire sheathing and putting things back in their home and enjoying this beaut again! Still need to rewire the cluster but she's alive!!
 

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darkness

Well-known member
Jul 15, 2009
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Cool deal. I wish I could have helped out with that wire. Dealing with a strained wrist after getting in a fight with a drill. My tcm is mounted to a bracket mounted under the battery lol. Trying to recall if the wire i spliced went from the ecm to the fuse block. Pretty sure it did.
 
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bogema

03 CC/SB LB7, 02 XCLB 8.1, 85 K5 6.2/6.5 S366
Aug 22, 2023
14
4
3
Michigan
All good sir. I believe that wire is the one to tap into for your kill switch if those are the codes your getting. I'd bet a few bucks on it.