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Discussion Starter #1
Added EFILive tune yesterday. Ran fine after that so I installed 5 position switch. No crank now. Uninstalled pin and still not start. A wire or something has wiggled out of place I believe. Pins appear okay.

Older guy that is not a mad, wrench slinging, wire snatching mechanic. But, you need to move ecm and wires around when installing a couple of pins. I tried to be easy since I make a living with this truck.

I can spin engine by jumping starter or by squeezing start relay. All fuses appear to be okay, but hey, it's me with a meter, so who knows.
#20 and #57 orange wires that are batt pos voltage do not have power key on or off.
#2 12 volt reference is also 0.

Anybody know what else to check?

Thanks guys!
 

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Added EFILive tune yesterday. Ran fine after that so I installed 5 position switch. No crank now. Uninstalled pin and still not start. A wire or something has wiggled out of place I believe. Pins appear okay.

Older guy that is not a mad, wrench slinging, wire snatching mechanic. But, you need to move ecm and wires around when installing a couple of pins. I tried to be easy since I make a living with this truck.

I can spin engine by jumping starter or by squeezing start relay. All fuses appear to be okay, but hey, it's me with a meter, so who knows.
#20 and #57 orange wires that are batt pos voltage do not have power key on or off.
#2 12 volt reference is also 0.

Anybody know what else to check?

Thanks guys!
PCM B fuse feeds circuit 440 (ecm c1 pins 20 and 57). You need to fix the cause of that issue first as that is the only bat + feeds to the ecm.
 

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Discussion Starter #3
Found it and replaced fuse. Cranks and runs!
Thank you.

Now, when I turn the key on to run, it spins over a couple times, stops and bumps again.
Just turning it to run, not start.
It has done it 8-10 times since putting it together an hour ago.

I'm sure that is another wiggled wire at the ecm? Any ideas on that issue?
 

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Has to be what you added. Remove it and try it again. It sounds like the ecm is seeing an unwanted crank request. That shouldn't be a wiring issue. What pins did you connect to at the ecm?
 

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Discussion Starter #5
5 way switch with EFILive. Pins into 49 and 69.
 

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Discussion Starter #7
Blue connector.
I have not removed pins to check operation without switch.
I guess that should be my next step.
I'll let you know.
Thank you.
 

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Discussion Starter #8
This morning, it tried to start on run, but would not turn over when turned to start. I drove it around yesterday.
I wiggled the wires to ecm and it tried to self start again when turned on, but would now turn over on start but not run.
Cranky but no runny.
Lift pump working, fuel 3/4 full, new fuel filter, primer firm.
I have not pulled pins yet. I'm going to pull them, but I don't believe they are the issue.
 

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Discussion Starter #9
After removing wiring harness, I discovered 3 pins that appear to be pushed into the ECM. The male pins that the connector pins slide over. Now what?
 

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Discussion Starter #10
Fixed it!
I took apart the ECM and pushed the pins back into place. Reassembled it properly and it fired right up normally. What a relief. They had not broken out of the ribbon. Thanks Chevy Tech!
 
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I can’t stress enough how easy the pins in most connectors and modules are to damage in one way or the other. It can really be a headache. If you do it every day you get a feel for them and know when the connector isn’t going together well. Most techs will stop at that point and make sure everything is good, some don’t. When you don’t do it everyday, it can be super easy to do something like what happened to you and not even think anything of it. No harm, no foul by the sounds of it and I’ll bet you won’t do that again. :)
 

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Discussion Starter #12
You are right sir. I thought I was being easy, but I guess I got a little crooked pushing it together. I get to play with my 5 position switch now. Try a burnout when I unhook the work trailer one day.
Thanks again!
 
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