Lb7 dies while driving fires back up drives fine no codes

[03Duramax86]

I have been having some issues with my 2003 lb7. Replaced the ficm a few months back, the my air dog2 165 went out. Airdog sent me out the new 4g pump and truck has been running fine. Thursday on my way to work truck started acting like it was running on 4 cylinders then died. Put it in park and the battery light was on, check all the terminals and everything was good, batteries are brand new. Got back in the truck and it fired right up no problems, checked for any codes with my cts2 and there was none. It happened to me again tonight. Has anyone else had this issue before? Any input would be appropriated.

 

[NC-smokinlmm]

Check all your grounds, especially the body and block.

 

[Molly]

Is that the "tractor mode"?


Sent from your girls iPhone.

 

[03Duramax86]

Idk im going to check all the grounds tomorrow after work.

 

[03Duramax86]

Update:
Checked all my grounds and I am still having the same issue. Truck will die while driving, I am able to pull off to the side of the road put it in park, it starts right back up. This doesnt happen everyday. Could the FICM have a problem with it?

 

[Awenta]

Check for codes with a better scanner.

Do you have an aftermarket radio?

Sent from my SM-N910V using Tapatalk

 

[03Duramax86]

Stock head unit. Ill have to grab my buddies V2 tomorrow night. I replaced the FICM with a good used one 4 moths ago.

 

[03Duramax86]

Update:

I am still having the same problems and I have checked all of the grounds and they are fine. I was able to get my buddies V2 and the only code that I am getting is C0550... Could this have anything to do with the problem I am having. Thanks in advance for any help.

 

[NC-smokinlmm]

Pull Ecm connections check for bent pins then reseat them...

 

[03Duramax86]

Update:

Checked all grounds pulled ECM and FICM checked all pins and have found nothing. Going to pull the valve covers and see if anything in there could be wrong. The last time I drove it and it died and I was able to crankit back up and continue driving, I hooked up the V2 and pulled 2 codes C0550 and a U1000. If anyone could elaborate on these or point me in the right direction would be appreciated.

 

[DAVe3283]

Which module set the C0550? That is the code a GM computer uses to report something is wrong with it internally. If it was the ECU, I would try a known good ECU off another truck.

The U1000 is a loss of communication between modules, and is common when there is a bad ground or when batteries get low. I see that stored on almost every 2003-2006 GM vehicle I see.

What you might have to do is borrow your friend's V2, and have it logging while you drive so you capture the shutdown. Hopefully that can shed some light as to why it shut down.

 

[03Duramax86]

Batteries are maybe a month old and I have been all over all the grounds. The ground to the EBCM was broke and I replaced the end. The ECU I replaced with a known good one in the beginning of February this year when I had another issue when the truck just died while driving and would crank but no start. That didnt fix it, turned out the FICM was bad and I got a known good used one and the truck was back up and running. I still have my original ECU that I can put back in and see if that fixes the problem I am having now. Does anyone know where i could get the main engine harness bale connectors on the top driver side so that I could replace them. Thanks DAVe3283

 

[03Duramax86]

Update:

Finally after tracing the wiring harness again, found out that my CPK sensor plug, one of the wires was not getting a good contact in the plug.

 

[DAVe3283]

That would do it. Glad you got it figured out! Thanks for letting us know.

 

[Ron Nielson]

Update:

Finally after tracing the wiring harness again, found out that my CPK sensor plug, one of the wires was not getting a good contact in the plug.

What's the CPK sensor? Don't believe I recognize that name.

 

[03Duramax86]

That is the Crank Position Sensor Ron. Thank you guys for your help!!