Starts then dies immediately

[White Duramax]

Have 2004 lb7 that I just rebuilt the engine on and just installed. I power washed the engine after the install and drove it about 15 miles. Cleared old faults after the test drive and restarted a few times fine. 2 hours later went to start the truck and it will start and immediately die. No engine faults, building around 7000psi rail when it starts, truck has a Fass pump. I have checked the bale connectors and ficm connectors, unhooked batteries, nothing helps. Security light is on all the time, it was on before I pulled the engine. The bcm code is B2948 security system sensor circuit voltage high- from what I have read this will not keep it from starting. Any suggestions. Thanks

 

[Harbin_22]

Did you try the VATS relearn?

 

[White Duramax]

Yes I tried one today. Same thing starts for a second and dies. Unplugged rail sensor and regulator one at a time, no difference.

 

[Muff]

Sounds like the bcm and ecm aren't communicating. Do you efi live? Can reflash the truck with the vats of.

 

[White Duramax]

I do have efi live. Have never messed with vats on it though. Do you know which parameters I need to change? Thanks

 

[Muff]

I do have efi live. Have never messed with vats on it though. Do you know which parameters I need to change? Thanks

Go to system. Change vats to disable. Badabing truck will run.

 

[Awenta]

Derail but will that completely disable passlock?

Mine gave me hell when my radio adapter went out and it took a while to figure it out. Plus when I swapped emcs I got the passlock light too.

Just curious if I could get rid of this god awful thing.

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[x MadMAX DIESEL]

Clear codes too


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[White Duramax]

Truck had a ppe tuner on it, I reflashed it and turned off the security option. Fired right up. Thanks for the advice.

 

[295PRO]

Well there you go.