when i turn on the key forward you can here the fuel pump come on, you turn it to start and it does for a second or so, and it dies again, it did that the other day and then it started to turn on and works great but today its doing the same thing that i wont turn on, so i connected the hp tuner and pulled this codes, hp tuners tech support said they were bcm codes and not to worry about it need some help. am not really worry about the brake codes but the others i don't know were start looking. thank you

[Brake] C0236 - Rear Wheel Speed Signal Circuit Missing (History)
[Brake] C0238 - Wheel Speed Mismatch (History)
[Brake] C0226 - LF Wheel Speed Signal Missing (History)
[Unknown] U1255 - Class 2 Communication Malfunction (History) (Immature)
[Unknown] B2947 - Security System Sensor Power CKT Low (History) (Current) (Immature)
[Unknown] B2958 - Security System Sensor Data Circuit High (History) (Immature)
[Restraints] U1096 - Loss of Communications with IPC (History) (Current) (Immature)
[Restraints] U1000 - Class 2 Communication Malfunction (History) (Immature)
[Restraints] U1064 - Loss of Communications with DIM (History) (Immature)

 

Unhook the battery and let it sit for 10 seconrds or so then hook it up and see what happens

 

KOEO (Key On Engine Off) is the check engine light on?

 

hey man i had very similar problems last week, check the negative and possitive terminals. my negative terminal would only get ground sometimes, causin it to work some days and not others. But try that and see wat happens

 

I had to disable my aftermarket remote start on my truck because it was interferring with the factory security causing it not to start.

 

so i checked the fuel pressure and it is between 50psi and 60psi, checked sparked and there is spark on both banks, checked every fuse and none of the are blow. what else can it be, is there anyway to troubleshoot a bad pcm.

 

Does it sound like it turns on for 1 sec(fires up) and then it turns off?

 

this is a wild guess but my wifes ml350 suv had a bad crank position sensor and it caused the suv to turn on and then die. We did not know it ws the cps until it was repaired. It had to be re-learned as well.

On my 99 silverado, the alarm remote start bypass replay went out and truck would not stay on for more than 1 sec. Almost if it ran out of gas. There was somthing about the security codes not all matching due. The security lights stayed on no matter what back then.
Hope this helps

 

Could be a bad ignition switch. That's why I asked if the engine light is on when you turn the key on and the engine not running. If it's not on you might have a bad ignition switch. Do you have a volt meter? Check the pcm and ignition fuses when the key is on and make sure you have good voltage to them.

 

VATS issue maybe?