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Discussion Starter · #1 ·
Okay I got a good one ,when my ficm module is bolted down in the bracket truck will not run. When I unbolted the three bolts and remove them it runs but it will only go 40-50 miles an hour and it cuts out under acceleration and load,Also when I press on the ficm with engine running it dies... any help please would be appreciated thanks
 

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Certainly sounds like an electrical issue (bad connection?) within the FICM. A good scan tool will give you a voltage reading for the FICM according to what I just Googled, so you could try that and/or wiggle and check the wiring and connectors going to it.
 

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Okay I got a good one ,when my ficm module is bolted down in the bracket truck will not run. When I unbolted the three bolts and remove them it runs but it will only go 40-50 miles an hour and it cuts out under acceleration and load,Also when I press on the ficm with engine running it dies... any help please would be appreciated thanks
Did you end up finding out what the issue was? Im curious because Im sort of having the same issue with my lb7.
 

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Discussion Starter · #4 ·
Okay so what I did was I ran a ground wire from one of the bolts on the ficm to an engine ground and then ran another ground strap to the frame. This got it to work better and I can now cruise 70mph but still down on power,I still think the ficm is going out because from what I researched the ficm is a self grounding unit and you shouldn't need to run an external ground wire but we all know how expensive those ficms are ,Its still throwing out no communication codes u1500 and u1000 so I'm 90% sure its the ficm and not a wire harness rub issue on my 05 LLY
 

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Okay so what I did was I ran a ground wire from one of the bolts on the ficm to an engine ground and then ran another ground strap to the frame. This got it to work better and I can now cruise 70mph but still down on power,I still think the ficm is going out because from what I researched the ficm is a self grounding unit and you shouldn't need to run an external ground wire but we all know how expensive those ficms are ,Its still throwing out no communication codes u1500 and u1000 so I'm 90% sure its the ficm and not a wire harness rub issue on my 05 LLY
Ok thanks for the feedback I appreciate it.
 
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