Won’t stay running

[IJLB1996]

I have a 2007 GMC Sierra 1500 5.3. When I have the key in ignition but not on when I open the driver door the dinger won’t come in when I turn the key to on position and try to start it it’ll run for a few seconds and then shuts off. None of my gauges come on and my radio won’t come on. My security light check engine light and airbag light are on. Had an aftermarket trailer brake hookup on it and I took it off. Negative battery post arcs when I touch the cable end to it. No idea what is going on 

[richard wysong]

I ran into the same thing almost today except the radio and blower would stay on with the key out door open, I disconnected the battery, cleaned the terminals, touched the cables together to clear the PCM/BCM and that cured it

[IJLB1996]

I’ll try that when I get home, I was thinking it was anti theft related but everything I’ve read and watched the security light flashes. Mine doesn’t flash, it will either come on and stay on or it will go right back off. Either way the truck will start for a second and then die. 

[richard wysong]

same thing, its like its not getting fuel but I checked and it had fuel pressure, the gauges didn't work and the scan tool would power up but not communicate. radio and blower would not shut off even with the key out and the door open, I had the battery disconnected for more than 30 mins while I went to the parts store, not sure if the key was on when crossing the cables, when I reconnected the truck started on its own via the remote start. I'm not sure what the problem was but was glad that fixed it

[IJLB1996]

I tried what you said and it didn’t work. I unhooked the cables and cleaned everything, touched the wires together and still had the same problem, no gauges or radio and it started for a second and then died 

[richard wysong]

I guess I just lucked out. the problem is probably the BCM. maybe someone else has an idea on how to reset it

[richard wysong]

maybe leave the battery disconnected over night and try again?

[IJLB1996]

I’ll try that, it’s been this way for almost 2 months. I’m just ready to try almost anything

[richard wysong]

does it have remote start? I was thinking that might have been the problem with the 1 I was working on. it still worked but then after the key wouldn't do anything. you could also try connecting the battery with the key on, that's a trick to reset alarm systems

[IJLB1996]

No it doesn’t have remote start just key start. It will start every 5 or 6 tries most of the time but for the most part it’ll start for a second then die or it won’t even try to start 

 

[richard wysong]

any change?

[IJLB1996]

No nothings changed. I feel like I’ve narrowed it down to either the BCM or my ignition

[richard wysong]

please post when you find the fix

[IJLB1996]

Changed ignition switch, no fix. Now my fuel pump isn’t pushing fuel up to my fuel rail I’m going to change the filter because I contacted the guy I bought it off of and he’s never changed it. And I’m going to change my key cylinder to see if it has a bad connection or something and see if that works

[richard wysong]

any luck? I saw a TSB for a similar problem on newer trucks that pointed to high resistance in the battery cables  or a bad ground to the BCM